Neoirieone, a diterpenoid of a new skeletal class from the red marine alga Laurencia cf. Irieii

Tetrahedron Letters,Vo1.23,No.38,pp Prmted In Great Britam

NEOIRIEONE,

Bruce M

3847-3850,1982

A DITERPENOID OF A NEW SKELETAL CLASS RED MARINE ALGA LAURENCIA CF IRIEII

Department Cornell

marine

systems

have

diterpenolds

neolrleone

neolrleol algae and

been

and

of Chemistry Unlverslty,

(2)

of the

genus

rearranged reported

Laurenaa 1

terpenolds.

from

The skeletal

upon Its structural 2 class

Clardy

- Baker Laboratory Ithaca, NY 14853

this

are noted

As

source

thex

prollflc

15 years

a consequence

over

of our

here the structure

and

diverse

synthesis

25 terpene-derived

ring

long

1" the

term

Interest

of a new diterpenold,

as In =2, 1s suggested for this new class based related blosynthesls to the lrieane (3) = dlter-

name neolrleane,

slmllarlty

for

In the past

from this source, we wish to describe (A)

Jon

dlterpenold of a new skeletal class, related to the lrleol The structure of "eolrleone has been Lsolated from Laurencla cf lr‘1811 by x-ray crystallographic analysis of Its corresponding reductlo" pro-

dlterpenolds, was elucidated

Red

Donovan

F

a dlbromlnated

Neouleone,

of halogenated

THE

Institute of Marine Resources Scripps Instltutlon of Oceanography La Jolla, CA 92093

Stephen

duct,

FROM

WI~~XUII Fenlcal

Howard

Department of Chemistry San Francisco State Unlverslty San Francisco, CA 94132

SUlNEO-y

0040-4039/82/383847-04$03.oo/o 01982 Pergamon Press Ltd.

and potentially

penold

As part of our chemotaxonomlc lr=ell

over Its dlstrlbutlonal

made at Bahia de Los Angeles,

studies of various

range wlthln

Laurencla

3 species,

the Gulf of Callfornla

was found to contain

One particular

several of the previously

lrleol C ($), irleol D (z), and lrreol E ($), but the malor metabollte extract)

was found to be a new trlcycllc

Fractlonatlon

L4 allowed

formulation

a basic

derivative

for x-ray analysis, neolrleol

orthorhomblc

flttlng of fifteen tic extinctions,

symmetry,

2@-Values,

density

by space group ~2~2~2~ dlffractlon

of the structure

of this compound

at C5, Cl1 and Cl4 could not be extracted

yield the crystalline possessed

structure

maxima with

(2) 5

and accurate

were

28 < 1140

were

of c

constants,

features

of

of the full stereoa

forming

from a least-squares

and $ = 16 185(62)i

of chlrallty

on a four-circle

3847

by slllca

In order to produce

determined

b = 11 756(85),

H Br203 20 32

collected

(10%

class

1 = was reduced with NaBH 4 in methanol to revealed that neolrleol

and the presence

with one molecule

2

x-ray photographs

lattice

a = 10 817(92),

conslderatlons

from these data

the ketone

Prellmlnary

Details

cf

lrleols,

of this collection

of a unique

/MeOH extract of the alga on silica gel, followed L3 neolrleone (&) as a viscous 011 Analysis of the spectral

yielded

chemistry

dlbromodlterpenold

L

collection,

reported

of the crudeCHC

HPLC purlficatlon,

crystalline

we lnvestlgated

were uniquely

the asymmetrlc diffractometer

Systema-

accommodated

unit using

All unique a variable

3848

Br I 3 R=RI=O I_ R=OH ,RI=H

18

--Br

9

4, R=Rl=Rz=H 5_, R=OH,Rl=H,Rz=OAc 6_,R=Rz=H, RI=OH speed w-scan and graphite this manner,

1489

model

conslstlng

sequent electron

density

electron

synthesis

matrix

density

least-squares

an anomalous

of 0.036 for the structure Figure chemistry

1 illustrates

In equatorial

with a 177" dihedral

refinement

nonhydrogen

has

structure

scattering

The cyclohexane

angle between

The double bond, C(6)=c(7)

was found by deconvolutlng

have converged 7 and 0.043 for the enantlomer

orlentatlons

for Lorentz,

1x1

polarl-

showed an approximate

showed all of the nonhydroqen

least-squares

the computer-generated

manner

check reflections

for bromine

as deduced using the anomalous

JoIned =n a trans -Br(l)

eventually

with anlsotroplc

correction

Of the 1619 data recorded

was not used In the data reduction

after partial

refinements

dlsperslon

monitored

of two bromlnes

syntheses

(1 54178;;)

(IFoI 2 30(Fo)) after correctIon

Perlodlcally

effects

but this decomposltlon

A phasing

CUKU. radlatlon

(92%) were ludged observed

zatlon and background 10% decrease

monochromated

atoms and lsotroplc to a conventIona

-O(l)H and -0(2)H,

The cyclohexene

a negligible

dihedral

Full-

atoms

hydrogens

discrepancy

(2) with absolute

The two six-membered

ring 1s In the chair conformation

The hydroxyls, them

showed the hydrogen

of neoirleol

of bromine

the Patterson and sub6 A difference ntoms

and Index

stereo-

rings are

with -C(16)H3

and

are In axial orlentatlons

ring has a 1,2-dlplanar

conformatIon

angle and the C(6)-C(7)-C(8)-C(9)

dihedral

3849

Frqure

arlrjle

1s

also zero

to the C(6). C(7).

The Lyclopentane

C(D) plane

rlnq 1s rotated so that the -C(18)HJ

It has an envelope

Br(21, C(7) and C(20) are III pseudoequatorlal The stereoLhfmlca1 On strwturai Ion-induced

desLrlptors qrounds,

LyLllzatlons

lrleane

and neolrleane

derived

sesqulterpenolds

sesqul-

and dlterpenold

of a typical dlterpenold opposltol

appears lwear

group 1s perpendicular

with C(15) servlnq

as the flap

and C(18) and C(19) are 1n axial posltlons

are C(l)g, C(~)R_, C(8JR_, C(lO)S, -

neo~rleone

systems

conformation

posltlons

1

C(ll)R, -

and C(14)R-

to be the biosyiithct;z pro&;ct

dlterpenold

precursor,

Of &Jo bXomonlUm9 Tne as Illustrated below

skeletons appear related III much the same way as 10 A plausible lntermedlate and sellnane 911 (8) =

could be structure

(as In 8 and 2) "la an acid catalysed

rlnq openlnq

the

Laurencla-

relatlnq

which 1s converted to the rearranqed 10 == of tne cyclopropane ring at CY-Cl0

+

these

skeletons

3850

Acknowledgements Research OCE80

14167

wishes

at the Scripps Research

to acknowledge

Instltutlon

at Cornell

was supported

NSF grant TFI80-19267

Howard

B M w

Howard Fenlcal

and W

Fenlcal,

Progress

and W

Fenlcal,

J

Orq

Norris,

J

Phycol

and J N

(1976). B M 4

Howard,

A M

Nonomura

43, 4401

11, 104

and W

under grant BMH

support

AND NOTES

1~ Phytochemlstry, Chem

Dlvlslon

by the NIH under grant CA 24487

for HPLC equipment

REFERENCES B M

by NSF, oceanography

was supported

Unlverslty

7, 263 (1981)

(1978)

(1975), W

Fenlcal,

Fenlcal,

Blochem

Syst

Phytochemlstry and Ecol

15, 511

8, 329 (1980)

3300, 2950, 1680, 1480, 1380, 1200, 1000, Neolrleone, [relay +1 00 (c 1 5, CHC13) IR (CHC13) -1 960 cm 6 7 00 , LRMS ml2 458/460/462, M+-~20 (~2~~28~r20~), 'H NMR (220 MHZ, CDC13) (1 H, s), 4 59(lH, dd, J = 12, 4 Hz), 4 34 (1 H, dd, J = 7, 7 Hz), 2 80 (1 H, d, J = 17 Hz),

1 34 (3 H, s), 1 30 (3 H, s), 1 11 (3 H, s) and 0 87

1 5-2 60 (11 H, m), 1 43 (3 H, s), 13C NMR

(3 H, s)

6 200 1 (s), 148 1 (s), 144 9 (d), 75 7 (s), 73 5 (s), 64 1 (d),

(CDC13)

60 7 (d), 51 8 (t), 49 2 (s), 47 6 (s), 45 2 (s), 37 5 (t), 35 7 (t), 31 2 (t) r

5

25 7 (q), 24 7 (q), 23 5 (q), 22 4 (q), 19 9 (q) 1 For neolrleol (acetate derlvatlve) H NMR (CDC13, 220 MHz)

29 8 (t) I

6 5 34 (1 H, d, J = 5 Hz), 4 45

(1 H, dd, J 12, 5 Hz), 4 23 (1 H, dd, J = 7, 7 Hz), 2 02 (3 H, S), 1 30 (3 H, s), 1 25 (3 H, s), 1 18 (3H, s), 1 07 (3 H, s) and 0 86 (3 H, s) 6

All crystallographic Materials

Science Center,

REDUCE and UNIQUE, block-diagonal

7 8

UnlVerSlty

Cornell

The prlnclpal

programs,

least-squaresrefrnement,K

Report No

W R

Hxotsu,

transform,

G

Cornell

Germaln,

P

K 0

Leonowlcz,

Laboratory

Mdrtln,

ORNL-3794.

No

Unlverslty,

Cornell

Unlveslty,

used were as follows 1978. BLS,

1978, ORFLS

(modlfled)

Levy, Oak Rldqe NatIonal

illustration

direct methods

Unlverslty

by the

Unlverslty,

BOND, structural

1978, MULTAN-76

Woolfson,

operated

programs Cornell

and H S

crystallographic

ORTEP,

Main and M

M E

Hxotsu,

Buslnq,

ORNL-TM305,

Oak Rldqe NatIonal

errors, K

r$jC

were done on a Prime 400 computer,

data reduction

least-squares,

full-matrx, Laboratory Johnson,

calculations

program

C

parameters

and

and fast fourler

of York

‘,al,,LIC",,, "~"..l+^.n-C_ CLyD‘aII"YL Cl_...^L-77^-- :yo, 502 (1965) tic-ca

Supplementary

crystallographic

been deposIted 9

W

10

S 8

Hall, D J

11

B M

Howard and W

Fenlcal,

(Received

Advances

In

lnformatlon

with the Cambridge

in Phytochemlstry,

Faulkner,

USA

J

Fenlcal,

8 June

Fayos and J J

deflnlng

Crystalloqraphlc

Org

1982)

Chem

bol

the structure

13, 1978, pg

Clardy,

of neolrleol

(1) have =

Data Center

J

, 42, 2518

Am

219 Chem

(1977)

sot

95, 7187

(1973)