Synthesis, properties, and identification of epimeric hepoxilins (−)-(10R)-B3 and (+)-(10S)-B3

Tetrahedron Vol. 49,No. 19.Pp.40994106.1993 PriitedinGreatBritain

0040-4020/93 $6.00+.00 0 1993Pqamon PressLtd

Synthesis, Properties, and Identificationof mimetic Hepoxilins(-)-(lOR)-B3 and (+)-(10s)~I# Ludmila

of

Institute

L.Vasiljeva,

Tatjana

AManukina, and Kasimir

Experimental Rndmgy,

Peter M.Demin, Margarita KJ’ivnltsk~

ALapitskaja,

Natiaml m Scientific Center RAMS, 1 Mcekvore&je St, Moscow 115622, RUSSIA

(Received in UK 22 January 1993)

Abetract' To characterise

the individual epimers of hepoxilin Bs, a new total synthesis procedure was developed consisting of subsequent condensations of enantromerically pure (2R,3S)-epoxy-5-undecynal with LiCmXXxCl and HCrC(C?iz)aC~Me, followed by Lindlar hydrogenation, and finally epimer separation. Derivatives of hepoxihn m-(lOR,llR,lZS)-Bs (free acid, methyl ester and acetate of methyl ester) are more polar on silica gel, have negative optical rotations [a]% -60.S0, -62.60, -25.P, respectively, and in 1R NMR spectra have the larger splitting of carbinolic H-10 signal (JIo,,u 5.0-6.1 Hz). Corresponding values for less polar hepoxilin ~(lOS,llR,12S)-BJ derivatives are: [a]% t73.50, t61.9, and -2.00; Jr&n 2.95-3.3 Hz. These data suggest that an epimer of hepoxilin Bs recently isolated by W.H.Gerwick et al. from red algae is m-(lOR,llR,12S)-Bs.

INTRODUCTION Hepoxilin B3 (HxB3) epimera,

in numerous

mammalian tissues

most important insulin

secretion

interest

natural

Although not been

have

“less”

islets.3 This bioactivity

acid cascade, are synthesized

at the lO-hydroxyl

most notably synthesis

HxBs

mollusk

This

was

restricts

Recently,

isolated

from

group.3

The

and glucose-induced

a steady increase

in the

hepoxilin has been found

several

tropical

red

marine

tissue.6

of hepoxilin

studied, 3 the physical

yet described,

hss created

and medical research.

in the Aplysia

the chemical later

of two epimers

role of hepoxilin is the stimulation of basal

in biochemical

systems,

and identified

stereochemistry

as mixtures

in rat pancreatic

of hepoxilin

in other algae*3

physiological

meiabolitee from the arachidonlc

B3 was

properties

first

reported

in 1983,’ and

of the non-racemic

the identllication

epimers

the

of HxB3

of HxB3 epimers to only “more” or

p~,7*9JO

The aim of this

study

was to provide

the meana to differentiate

and identify

the HxB3

epimers. To acccmplish this, a new synthesis pmcess ~indivldualHxH3epimsrs(l8J3)wasde~ and

their

properties

relevant

to epimer

differentiation

4099

and

identification

are

described.

L. L. VASILEVA et al.

4100

RESULTS

of XepoxQin R7 Xpimere

Chemical Synthesis A synthe,sie

of

non-racemic

(Scheme 1). Enantiodirected Sharplees

methodii

enantiomeric high by

yield

Pyridinium described8

L-(+)-diethyl

tartrate

(t&e.) 88%. Enantiomeric of correeponding

a by-product

shifts

of the OAc-signal

dichromate

oxidation

performed

of

recrystallization.

was easily

E.e. values

in the presence

from the oxidation

fact constitutes

further

20-carbon

condensation

chain

could carbon

be

involved

performed

chain

ClCHE~CLim

evidence

proceaaing a

the

with

A condensation

in Batisfactory

asymmetric

center

By analogy

with HxB3

were

deduced

derivatives*

from

6a,b into the mixture of HxBs epimers

The final chloroalcohol

chain elongation mixture

in DMF, which

20-carbon

methyl

5-hexynoate

6a,b with

produced

a high

yield

new method of terminal acetylene will be published carbon

chain

in a separate

construction

direct

condensation

latter.

This

The final

step

hydrogenations to controL7 with

of.the arrays

Previously

selectivity

up

hydrogenationa hydrogenation presented

yielding

secure

high performance prepared

epimers flash

of carbinolic

chain was performed in the presence

ID-H-signals. to the

(vzde infra).

ratio

by condensation

methyl ester

mixture

halogenides two-step

the total

is the simultaneous

of

yield

7a.b.

This

in mild conditions method of hepoxilin

in comparison

with

the preparation synthetic

the

of the

scheme which

Lindlar

hydrogenation

present

we

selected

selectivity

up

ester

of 3 triple

bonds of HxEt3 eeter 8a,b. Similar multiple

in Lindlar

hydrogenation the

conditions

to 95%. The

mixture

&b

and diffi&t

of the ester for

detailed

fepimer

this

and

conditions

ratio

rat-‘7a.b similar for

thia

arb = 74~26) are

eection,

of HxBs methyl

chromatography

by standard

6a,b

of CuI, NaI, and IQ&O3

acid and does not require

97% of the BxB3

in the Experimental

propargyl

at the newly formed Cl0

with the same syntanti

4 doubles

succeeded

the

this

a new

to ch@oalcohols

of different triple bonds are believed to be low-yielding

we have

As

3. the

verified by the conversion of the epimeric

with propargylic

7a,b into (Z)-double

to 80%.8 At

which

The individual 9a.b were

ester

as

one.

in the eynthelsia

bonde of hexahydro-HxBs

acid.

we developed

rise

an uncommon example of a non-convergent

than e convergent

to conetruct

4 with lithiated

shifts

communication. 14 The developed

from aldehyde

5 formed

(8 4.48 ppm) was attributed

of hexadehydro-HxBs

alkylation

with S,8-nonadiynoic

constitutes

is more effective

Ia,b

to reach

to those

of epoxyalcohol

me-4

(132X),

of aldehyde

signal

ester

5,8-nonadiynoic

yields

the NMR chemical

majnr 8yn epimer 6e. This assignment was subsequently

which

with the expectation&

purity

aldehyde

yield (71%) giving

the more shielded

reagent

4.” In this case,

the dimeric

with

modest

determined

shift

analogous

in accordance

racemic

condensation

at best

elongation.

proceeded

sub&rate,

as a mixture of epimers in a ratio of 71:29. The epimer configurations

mixture

were

[Eu( hfc)31

3, entirely

of the enantiomeric

of

with with

of the chiral

(2R,3S)-epoxyaldehyde

homogenous product,

3

enhanced

enantiomere.

epoxyalcohol

afforded

of the racemic

an additional

the

the

a new method

by

28 by the catalytical

(2S,3S)-epoxyalcohol

of the product

in the acetate

rat-3,

was a dieetereomerically

Previously,8

method for

was

produced

purity

acetates

for the racemic compound

as distinguished

chloride,

HxBs 1-b

tris[3-(heptafluoropropylhydroxymethylene)-D_camphoratel

different

hepoxilin

of

up to e.e. >98% by low-temperature

europium(II1)

This

epimers

epoxidation of 1-hydroxyundec-I(E)-en-5-yne

using

excess

1H NMR analysis

induced

AND DISCUSSION

esters

(HPFC).

methods.

8a,b were

Corresponding

isolated free

from

acida

the mixture

Ia,b

by

and acetates

4101

Epimeric hepoxilins (-)-( lOIt)-B, and (+)-( KU)-B,

Scheme

IK2C03, CuI, NaI

la& So&:

!2a,b:

R=R’=H R=Me,R’=H R = Me, R’ = Ac

OH

epimer a:

& OH

epimer b:

$9 10

1

4102

L. L. VASllJJZVA et al.

of Eepoxih

Properie

Selected epimer

BJ J$pimer8

properties

differentiation

“a”) of all investigated and

possessed

reproducible could the

single

Table

be

of

hepoxilin

rotations.

of weakly by

rotating

epimer

(for

or

of optical

example

see

Theee

rotation

below),

at two wave lengths,

for

(indexed

increments

hae already

are

not easily

we

been

regularities

used

recommend

the

e.g. 388 and 578 nm, for of

optical

(see Table 1) and are leas sensitive

published

significant

such es hepoxilins, and therefore

eicosanoide. If An even more valuable

1R NMR data. Already

most

10&l-sy=epimers

more polar on silica gel chromatography

oily substances,

identification.

magnitude

to hold for acetates

1. The Properties

were

in optical rotations

larger

derivatives

1. (lOR)-

As the values

A very efmilar criterion

[ale values.

HXBa epimer

in the Table

for identification

used

of significantly

found

optical

of the difference

is provided are

hepoxilin

for small quantitiee of unstable

purpose

chirality

these

presented

hepoxilin Es derivatives

negative

not always

application usually

of

are

rotation

are

to impurities

than

as a simple indicator

of

meana of epimer identification in NMR data of HXBs epimer@

9a,b as well.

of C-10

Epimers

of Ifepoxilin

Ba

rH NMR data ____________________~~~~~~~~~~~~~~ WmP-

Deri-

C-lO-

Rrt

ound

vat&e

epimer

eilice gel, TLC

free

la

R (wn)

0.28

E&m-

Ial678 (c in CHCls)

-60.60

-1380

solvent

CDCls

H-W eignaf _____________-_____-----J, Hz

8, DDm

9-10

lo-11

4.33

7.4

5.1

4.70

7.9

2.95

4.33

7.7

5.0

4.67

8.5=

3.3

5.61

8.8

6.1

5.89

8.4

3.3

(c 1.17)

acid lb

Ial%

S (anti)

0.29

+73.50

t1750

fc 0.67) ________________-___-_____________I___~~~~~~~~~~~~~~~~~~~~~_~~~~~~~~~~~~~~~~~~~~~~~~

8a

methyl

R

0.13”

8b

-62.6“

-1300

CDCla

fc 0.89)

ester S

0.16

+6l.Q”

+1730

(c 1.09)

acetate

Qa

R

0.41d

9b

ester

-25.20

-640

CsDs

(c 1.68)

methyl S

0.42

-2.00

+40

(c 0.82)

a) system dat&

EtOAc-hexane

d) WIe-P&O

(2~3); bf EtOAc-hexane

(85:15).

(1:4);

c) note the correction

of publiehed

.

Epimeric hepoxilins (-)-( lOR)-B, and (+)-( l(S)-B3

Configuration

Aseignment

The data

data for a single W.H.Gerwick

of an Unknown

et

epimer only are available. al.4.5 isolated

filamentosa, and Murrayells for which the following 9.2 Hz, Jsn of

algae

Table

from

&t Epimer

to identify

tropical

red

Ba epimers

hepoxilin

This may be illustrated

Platysiphonia

algae

mini&a,

the later

published:

deduced,

but

can be estimated

1. An agreement

is observed

the

[al%

-10.90 (c 0.11, CHCh),

relative

with

ease

in other

(12s)

(lO,ll)-configuration

by comparing

cited

configuration

remains

unknown.

NMR data with those

in

HxBa isolated

la.

‘We hops that the information presented B3 epimers

Cottoniella

6m-n 5.67 ppm, Jam

with the data for epimer “a” only. Therefore

from red algae’ is (lOR,llR,lPS)-HXBJ of hepoxilin

if the

example.

periclados an epimer of IixB3 in the form of the acetate methyl ester

data were

be

even

by the following

6.4 Hz (in C6Ds). From the sign of optical rotation the absolute

HXBJ can

However,

Hepoxilin

in the Table 1 make it possible

4103

herein will help in differentiation

instances

and identification

as well.

EXPERIMENTAL GeneraL

Optical

mercury

lamp lines.

equation:

[a]o

rotation

were

Rotation

measured at the

on polarimeter

sodium

= 1.34 x [al578 - 0.34 x [a]%

micro hot stage.

Infrared

spectra

were

fused

was

performed

silica

conditions

see

apparatus

using

capillary

ref.8.

Thin layer

(TLC)

plates

was

“Usual anhydrous residue were

Kugelrohr

workup”

Pyridinium

(Aldrich)

prepared

according

acid were

distilled

(230 mg)

mmol) and cooled mixture

to -2O%,

used

catalyst,

in glass

before

dec-5-yne

(88

t-BuOOH

was stirred

at stated

on

other

the

same

temperature.

aluminium-backed (TLPC)

TLC sheets

was run using

High performance

flash

solvent, at

H

plates. Vacuum distillation

temperatures

the stated

n-BuLi

of an oven.

drying <40%,

All reactions

of the extract and

drying

and sample

by

of the storage

argon. solution (Fluka),

A solution

L-(+)-diethyl

of anhydrous

t-BuOOH

tartrate

were purified

and

in CHzClz was

2 and 5-hexynoic

of the latter was prepared

and solvents

by etherial

by standard

methods.

use. (3). A suspension cooled

mg, 0.31 mmol) were

to -5% added

of powdered, L-(+)-Diethyl sequentially.

activated tartrate After

(1.72 ml, 6.5 mmol, 3.8 M in CHzClz) was added

10 min, whereupon

an open

phase,

obtained

et al. ii. 1-Hydroxyundec-2(E)-en-5-yne reagents

using

2 x 16 cm or 3.5 x 18 cm with Kieselgel

of purified

as received.

in 40 ml of CHzClz was

Ti(OPr-i)4

by

with

(5=0). Gas-liquid

at stated

of 2 mm thickness.

at 2ooC in 1.3 GPa vacuum.

atmosphere

All other

(ZS,3S)-l-Hydzvxy-ZJ-epoxyun

were

to be 2000 theoretical

(Aldrich)

the

MSL-2C0 (200 MHz)

stationary

chromatography

by known methods. Methyl ester

methyl&ion.

were

UV-254

of

using

with a Boetius

LKB-2091

SE-30

eV)

in vacua on rotoevaporator

to K.B.Sharpless

synthesized

diazomethane

weight

were

columns

to extraction

dichromate, Lindlar

Ti(OPr-i)r

gel layer

using

apparatus

in a static

preparative

was determined

refers

until constant

Solvents

silica

MgSO4, concentration

performed

sieves

with

performed

Column effectiveness

done using

(22.5

was with Silufol

Whatman glass (Fluka).

determined

as an internal standard

mass-spectra

(0.2 mm). Thick layer

was

with Me&

wavelengths

calculated

75 IR-spectrophotometer

inlet of the sample into the ion source

chromatography TLC

were

(0.3 mm x 25 m) with

column

with silica gel layer chromatography16

points

on a Specord

on a chromate-mass-spectrometer

Electron-impact

a direct

A at the

were obtained on either Bruker

or a Tesla BS-587A (80 MHz) spectrometers, chromatography

Polamat

(A 589 nm) were

Melting

obtained

liquid films or CC14 solutions. 1H NMR spectra

tubular

D-line

a solution

of alcohol

the

4A molecular (86 mg, 0.39 mixture

and the

was

resulting

2 (515 mg, 3.1 mmol) in CHzClz

L. L. VASIIJEVA et al.

4104

(3 ml) was ml). The

added.

Stirring

mixture

emulsion.

An

was

aqueous

added

and distillation of residue,

(0.4

for layer

at -2OW

-11.80

3 are

(c

ml, 30%) saturated

separation.

After

[a]%

at ea. 3.58 (major) afforded

1.14, WC%)

identical

2.5 h before

addition

45 min resulting with

the usual

NaCl,

and

workup

aa a colorless

to those

and

published6

crysWline

substance:

t10.70 for

for

30 min

(CHzClz, 4 x 2 ml)

3.60 (minor).Three

pure

[a]%

after

(2

white

mass (514 mg,

-11.10 (c 1.83, CHCls), e.e. 88% according

an optiaally (lit.i’:

of water

in a stable

acetate with addition of 20 molar X of Ru(hfcb

sygnals

from hexane (10 ml) at -78% 34oC, [a]%

for

epoxyalcohol 3 was obtained

iH NMR analysis of corresponding OAc-group

for

up to 25%

lOO-110%/0.03 GPa, m.p. 32,5-33.1%,

of singlet

epoxide

maintained

to warm

NaOH solution

methanol (5 ml), were 91X), b.p.

was

allowed

using

the ratio

recrystallixations

yield 65X, e,e. >98%, m.p.

enantiomer).

the racemic compound

Spectral

data

of

rat-3,

(2R,3S)-2,3-I&mxyundec+-yn-l-al (4) and (9S,19R,1#S,l5S)-9,10;14,15-Bimpoxp12-oxatricoma-6,17-d&m-II-one (5).These were obtained concurrently by oxidation of the alcohol 3 in an analogous colorless (c

manner

liquid,

[a]%

2.27, CHCb);

individual CH2),

to that described

unlike

the

diastereomer.

Other

properties

product

of these

optically

(~,-%@Zl-

and t=W=S=kl*-

after

substances

was quenched

(EtGAc, 160 ml) resulted removal

1:4); IR (film, cm-i): 701 (C-Cl),

are

4.18 (d, J 1.8 Hz, l-Hz), o.?),

J 3.0 and

identical

5 is an

1.37 (m, 6 x 3.48

12.2 Hz, 13-H).

to those

described

for

b=-&b).

rat-4

gave

ratio

over

in an orange

of saturated

4.48 (m, intensity

mass spectrum

of racemic alcohols

211 (0.81, 201 (~~-~l-H~l+,

lOO), 81 (761, 67 (881, 55 (55f,

ether

solution

(20

solution was in hexane

rac-6a.b

as a

Rt 0.17 (EtGAc-hexane, 6 0.89 (t, J 6.0 Hz,

2.58 (m, ?-Hz t OH), 3.21 (m, 5-H + 6-H),

O.?lH, 4-H of “a” epimer),

(lOO%,

NH&l

oil which in benzene

iH NMR analysis);

2.14 (m, lo-Hz),

to -78%

of 5 min followed

elution by EtGAc solutions

mixture

?1:29 by

period

(600 mg, 2.78 mmol) in diethyl

by addition

epimer

the

1259 and 3423 (OH); lH NMR (86 MHz, CD%):

Me), 1.38 (m, II-HZ t 12”Hz t 13-H&

([M-Cl]‘,

active

11.0 mmol) was added

oil (505 mg, 71X, epimer

([V-C”]‘,

the ester

-21.80

(m, 8-H t 14-H + 15-H),

4.54 (dd,

on silica gel column (5-40 nm, 10 g). Gradient

4-H of “b” epimer);

material,

2.94-3.42

12.2 Hz, 13-H),

of the racemic aldehyde

5 to 20K) and solvent

colorless

starting

4: a

oil, [a]%

b.mb=~-----

10 min the reaction

ml). The usual workup (from

racemic

The aldehyde

chloride (909 mg, 122 mmol) in diethyl ether (10 ml) was cc&d

3 min by a solution

adsorbed

racemate.*

5: a colorless

samples.*

(7.3 ml, 1.5 M in hexane,

(10 ml). After

the

J 6.3 and

racemic

A solution of propargyl

from

2.60 (m, ~-HZ t l6-Hz),

4.04 (dd,

corresponding

n-BuLi

corrdsponding

IH NMR (80 MHz, CDCla): 8 0.90 (t, J 6.1 Hz, 2 x Me),

2.14 (m, ~-HZ t 19-H&

(d, J 1.6 Hz, 10-H),

for

t40.4O (c 1.25, CHClsf. The dimeric ester

m/z, X of rel.intensity): 0.71, 183 ([M-C~Hlil*,

4.69 (m, intensity 237 ([M-hOI+,

0,298,

0.41, 219

1.41, 151 (I@-WC,

91, 95

53 (491, 43 (33), 41 (56).

(4R,SR,6S)-and (4S~5R,6S)-l-Chloro-4-~droxy-5,6-epox.vtetradeca-2,8-d&mes (6a.b).The condensation

of the enantiomerically

pure

the racemic sample to give a colorless b.p.

19OW/O.O6 GPa,

described

above

for

[a]%

-6.3O (c

the racemic

aldehyde

4 was performed

oil which crystallized 1.53, CHCb);

other

as described

in the refrigerator:

properties

were

above

for

m.p. 17.5oC,

identical

to those

sample.

Methyl(1ORS&RS,12SR)-and (l~~llRs,l2sR)-L~Hy~-ll,~~~l~~ (ma-7&b).A mixture of each anhydrous, pulverized CuI (64.1 mg, 0.34 mmol), Neil (169 mg, 1.13 mmol), KzCOa (123 mg, 0.89 mmol), and 5-hexynoate

DMF (0.5 ml) was

(98 mg, 0.78 mmol, in C,4 ml of DMF) and

mmol, in 0.4 ml of DMF) were

successively

added.

prepared. chloroalcohol

The mixture

was

The solutions rac-6a,b stirred

for

of methyl

(85 mg, 0.33 5 h at 21%

Epimcric hepoxilins (-)-( IOR)-B, ad (+I-(lOS)-B3

before

quenching

46 ml) followed

with saturated

by filtration

silica gel (3 g) resulted

aqueous

Met&l

except

of

in isolation

ratio azb = 74~26 by GLC analysis respects

NH4Cl solution

of the resulting

the epimer

(40 ml). Usual

workup

yellow oil in EtGAc-hexane

triyne

rat-7a,b

of Bu~ezSi

ratio

4105

ether,

This sample was identical

by the other

active

analogous

to the racemic

properties

were identical

epimere

sample

was obtained

as a pale

to those

yellow

from chloroalcohol oil, [aI%

of the racemic

in all

way?

~lOR,li&l2S)-and (1oS,11~12S)-10_Hyd~-11,12~~ye~-5~,14-~~~

The mixture of optically

J&b). mixture 6a,b entirely

-7.70 (c 1.25, CHCb);

all other

sample.

Meti@ ~10&11&12S)_ and (1~,11~1~~1~~d~11,12~~e~~~2~~~2~,14~2~~ (Hepmilin Bs Methyl Eders) (Sa,b).A mixture of Lindlar catalyst (350 mg), quinoline pl), and benzene (15 ml) was saturated 7a,b

(350 mg)

atmosphere absorbed). added

in benzene

at 15% until The suspension

to the filtrate,

by

amount).

were

and

the mixture

repeated

according

(by

isolated

15~85, 4 deve~pmen~)

using

HPFC

catalyst

by

absorption

poured

Epimer 8a: a colorless

by

123

on a aluminium was eluted

EtOAc (120 ml) to give 95% of trienes

was

(350 mg) was

pli 7.0), and the quinoline

15:85) followed

(EtOAc-hexane,

in a hydrogen

hydrogen

the filtrate

of Bu+MezSi ether)

of mixed fractions.

stirred

Lindlar

for 50 min (total

Brockman,

GLC analysis

was

(60 min, 38 ml of hydrogen

a hydrogen-presaturated

The mixture was filtered,

(77:

(35 ml, 1 atm). A solution of triyne

had ceased

(5:95, 120 ml). The column was eluted

oil (346 mg) containing epimers

was filtered,

(19 g, II activity

EtOAc-hexane

added

absorption

and hydrogenation

ml, 180% of theoretical oxide column

at 154: with hydrogen

(17 ml) was hydrogen

3 x

as a yellow oil (104 mg, 91.5% epimer

see ref.7).

to those obtained

(benzene,

(1:4) solution through

8a,b.

TLPC

a yellow

Individual

(EtzC-benzene,

oil, yield 211 mg (59x),

[aim

(x, nm): -1950 (366), -1470 (406), -121.40 (436), -71.80 (546), -64.90 (578) (c 0.89, CHCb). Epimer 8b: a colorless oil, yield 74 mg (21X), [aI= (h, nm): t238” (366), +172” (406), t141.1 (436), +75.80 (546),

t65.40 (578)

(c

1.09, CHCh).

For other

data,

see Table

1. Chromatographic

as

wellas spectralpropertiesof optically active samples were identical to those of the corresponding racemic

ones.8

Ifepoxilin (lOR)~& (la).A solution of methyl ester

8a (13 mg) and LiOH (47.6 mg) in a mixture

of methanol (7.3 ml) and water

at 23oc for 90 min. The mixture was diluted

with water acid.

The

hepoxilin

(4 ml) was stirred

(30 ml) and diethyl ether usual la

workup

(Et&,

(30 ml) and carefully

3 x 30 ml) followed

(11.4 mg, 91%) a6 a colorless

oil, [a]=

(&

(436), -76.90 (546), -63.20 (578) (c 1.17, CHCls); IR (CC& MHz, CDCb):

6 0.88 (t, J 6.0 He, 20-H&

Hz, ~-HZ), 2.04 (m, 4-Hz + l6+2), tdd,

J 5.1 and

~~~ from ester

7.4 Hz, 10-H),

flCs)-Bs

(lb).

t85.80 (546), t76.60 (578) (m, I7-Hx + I&Rr +

13-Hz),

2.87

OH), 4.70 (dd, HepoxZn

This

8b: a colorless (C

(m,

7-H?

J 2.95 and

2 x OH),

1.74 (quintet, 11-H),

nm): -2010 (366),

2~3) afforded

-1500 (406),

-123.90

cm-l): 1715 (C=C), 3400 (OH); IH NMR (80 1~Hz),

5.45 (m, olefinic

in an analogous

78%, [al23(A, nmh

0.67, CHCh); ‘H NMR (80 t

to pH 3 by 3% hydrochloric

(EtOAc-hexane,

1.28 (m, 17-X2 + 18-H2 +

obtained

oil, yield

t l*Rz),

TLPC

(quintet,

1.75

2.36 (m, 2-Hz t 13-Hz), 2.92 (m, ~-HZ t 11-B t 12-H),

5.16 (br.s, was

acidified

by

3.06

7.87 Hz, 10-H),

MHZ,

J

See also

to epimer

“a*

4.33

Table

1.

Starting

+252O (3%)~ +186' (406), t156.2’ (436), CDCh): 6 0.89 (t, J 6.0 Rz, 20-H&

J 7.1 Hz, 3-H& (dt,

fashion

6H).

J 7.0

1.27

2.05 (m, 4-He + 16--H& 2-36 (m, ~-HZ

2.56 and

5.41 (m, olefinic

6.51 Hz,

12-H),

4.15

6H). See also Table

fbr*s,

2 x

1.

(lOR)-a,Acetate MefAyl &Wer (CI& A mixture of ester 8a (17 mg), acetic anhydride

(157 mg), and pyridine

(430 pl) was maintained

(2 ml) the mixture was evaporated

at 2VC

for

18 h. After

dilution

at 2CPC in vacua at 1.3 GPa to dryness.

with benzene

The residue

was

4106

L.L. VASILIEVA~~ al.

purifiedby TLPC (Et&-benzene, X:85) to give the acetate9a (17.7mg, 93%) as a colorless oil, [a]= (h,nm): -79.80(366),-66.70(406),-50.00(436),-29.20(546),-26.20(578) (c 1.68,CHCL); IR (CCL, cm-l):1745 (C=O);1H NMR (200 MHz, C&s): 6 0.90 (t,J 7.0 Hz, 2O-HJ),1.24 (m, 17-Hz + l&H2 + 19-H& 1.64 (quintet,J 7.0 Hz, ~-HZ),1.70 (s, OAc), 1.97 (m, 4-Hz + l6-Hz),2.14 (t, J 7.4 Hz, ~-HZ),2.30 (m, 13-Hz),2.92 (m, ~-HZ t 11-H t 12-H),3.40 (s,COOMe), 5.45 (m, olefinic6H), 5.61 (dd, J 6.1 and 8.8 Hz, 10-H); mass spectrum (7ooC,m/z, % of rel.intensity): 392 ([Ml+, 0.2), 361 ([M-OMe]*, 0.5), 350 ((M-CH?COl*,0.5), 332 ([M-AcOHI', 8), 301 ([M-OMe-AcOHl*, 5), 281 ([CLCu]*, 4), 221 ([281-AcOH]*,48), 210 (51),160 (44),81 (100).See also Table 1. Heparilin(lOS)-& Acetate Methyl Ester (96). This epimer was obtained from ester 8b similarly to epimer "a" as a colorless oil,yield91%, [a]" (h,nm): t1.20(366),t3.60(406),-1.20(436),-3.60 (546),-2.40 (578) (c 0.82,CHCb); IR (CClr,cm-l):1745 (C=O); lH NMR (200 MHz, CsD6):6 0.92 (t,J 7.0 Hz, 20-Ha),1.28 (m, 17-Hz + l8-Hz + 19-Hz),1.63 (m, ~-HZ),1.72 (a, OAc), 1.98 (m, ~-HZ t X-Hz), 2.16(t,J 7.4Hz, ~-HZ),2.27 (m, 13-Hz), 2.92 (m, 7-Hz + 11-H + 12-H),3.40(8,CoOMe), 5.48 (m, olefinic6H), 5.89 (dd, J 3.3 and 8.4 Hz, 10-H). See also Table 1. Acknowledgements. Financialsupport from Russian programmes *Biotechnology"and "Diabetus" is gratefullyacknowledged. REFERENCES

AND NOTES

1. Synthetic Study of Hepoxilins,Part 3; for part 2 see: Demin, P.M.; Vasiljeva,L.L.; Myagkova, G.I.;Pivnitsky,K.K. Eioorgan. Khimia 1991, 17, 1133-1140. 2. Pace-Asciak, C.R.; Granstrom, E.; Samuelsson, B. J. Biol. Chem. 1983, 258, 6835-6840. 3. Pace-As&&, C.R; Martin,J.M. Prostaglandins, Leukotrienes and Medicine 1964, 116, 173-180. 4. Moghaddam, M.F.; Gerwick, W.H.; Ballantine,D.L. J. Biol. Chem. 1990, 265, 6126-6130. 5. Gerwick, W.H.; Bernart, M.W.; Moghaddam, M.F.; Jiang, 2.D.;Solem, M.L.; Nagle, D.G. Hydrobiologia 1990, 204/205,621-624. D.; Shapiro, E.; Zipkin,R.; Schwartz, J.H.;Feinmark, S.J. Proc. NatI. Acad. Sci. 6. Piomelli, USA 1989, 86, 1721-1725. 7. Corey, E.J?;Kang, J.; Laguzza, B.C.;Jones, R.L. Tetrahedron Lett. 1983, 24, 4913-4916. 8. Demin, P.M.; Vasiljeva,L.L.; Lapitakaya, M.A.; Belosludtsev,Yu.Yu.; Myagkova, G-1.; Pivnitsky,K.K. Bioorgan. Khimia 1990, 16, 1125-1133. 9. Pace-Asciak,C.R.;Martin,J.M.;Corey, E.J.;Su, W.-G. Biochem. Biophys. Res. Commun. 1985, 128, 942-946.

10. Pace-Asciak, C.R.; Martin, J.M.; Corey, E.J. Prog. Lipid Res. 1986, 25, 625-628. 11. Gao, Y.; Hanson, R.M.; Klunder, J.M.; Ko, S.Y.; Masamune, H.; Sharpless, K.B. J. Am. Chem. Sot. 1987, 109, 5765-5780. 12. Compounds 3 and 4 possess the same absolute configurationat C2. The change of the configurationnotation does not imply any epimerizationand is due to change of the substituent priorities. Acetylenic Chemistry, 2nd Edition;Elsevier: Am&-Oxford-N.Y.-Tokyo, 13. Brsndsma, L. Preparative 1988; p. 25. 14. Lapitskaya, M.A.;Vasiljeva,L.L.;Pivnitsky,K.K. Synthesis, accepted for publication. 15. Corey, EJ.; Albright,J.O.;Barton, A.E.;Hashimoto,S. J. Am. Chem. Sot. 1960,108 1435-1436. 16. Vasiljeva,L.L.;Pivnitsky,K.K. Deposition in VINITI, 1986, V.86, X6390. 17. Corey, E.J.;Hopkins, P.B.;Munroe, J.E.;Marfat,A.; Hashimoto,S. J. Am. Chem. See. 1980, 102, 7986-7987.