Photodecarbonylation of keto-monosaccharides

Tetmhedxoa Letterslo. 42, pp 4011 - 4014. OPergemon PreaaLtd. 1978. Printedin Waat Brit&h

PHOTODECARBONYLATION

Kurt Heyns, Institut

ftlr Organische

OF KETO-MONOSACCHARIDES

Rainer

Chemie

Neste

und Biochemie

Martin-Luther-King-Platz

The photolysis coworkers From

of carbohydrate

und Michael

6,

uloses

Paal

der UniversitBt

2000 Hamburg

has recently

13,

Germany

been studied

by Collins

and

” 29 3). our own

we know,

on the photolysee

compounds

lose

carbon

of

to study the compounds

monoxide

to yield.

one isomer

of the

influence

of ringrize

with furanoid,

pyranoid

on this

reaction,

we prepared

the

and septanoid

ringsystems:

1.2,5.6-Di-O-iropropylidene-a-D-ribo-hexulofuranose-3

r,

1,2,4,6-Di-O-benzylidene-a-D-ribo-hexulopyranore-3

2 -’

1.2.4,

3,

5-Di-0-isopropylidene-a-D-ribo-hexuloeeptanoee-3

l,2,3,4-Di-O-ieopropylidene-o-D-xylo-hexuloseptanose-5 four uloses 5)

compounds have never

have been prepared by

oxidation

been prepared

NMR-spectroscopy

ieopropylidene-d

before.

yielding

mixture

Their

a

But from two sugars compound. which has

and

pyranoid

products

when

the photolyeates

yields

already

10 %

structures

gluco-

compounds

2,

have been elucidated

compounds

2,

by

from

IR and

2 and 2 have been reduced of 1,2,4&j-Di-O-

photolysed

1.2.

been described

1

acetates and g

3

have been

no

tendency

to form

3 and 4 we were

of carbon

monoxide

by-product 4011

ring-

able to isolate

from

the mother-

3,4-Di-0-ieopropylidene-a-D_ribopentopyranose as a

1,3,3,4-Di-

in the usual manner,

compounds

by loss

2 andp

2 and

and &.

showed

in dry benzene

septanoid

formed

In addition,

4.

of their

of the

and 4

and I ,2,4,~Di_0_isopropyIidene-~-~Ioseptsnoee

compounds

that are obviously 2

corresponding

of 1,2,3,4-Di-O-isopropylidene-d-D-glucoseptanose

Qy ~-spectr06copy

The furanoid

known

70/30 mixture consisting

O-isopropylideneB-Gidosept~ose5 oharaoterised

the well

). Furthermore,

-D-glucoaeptsnoae

from 3 and a 50/50

from

5.

with Ru02 6) . As far as we know,

( see table

with sodium borohydride

contracted

4)

1,6-anhydro-hexopyranuloses

pentopyranoee.

In order following

experiments

that these

corresponding

All

Hamburg

from

the reaction

of riboee

1,

4012

No. 42

(7)

(3)

(4)

r.&,

@gl

lo.

Lj2

4013

Chemical

Cmp.no.

shifts

( values,

TMS

and coupling

H6

H6’

constants

3 (Hz) at 270 MHz

solvent

Hl

H4

H5

PhCH

Ar

OAc

Isopr.

CDC13

5.99

4.66

-

4.44

4.22

4,5

3.89

6.09 5. 61

7.33

-

-

3

CDCl,

5.55

4.83

-

4.83

4.45

4.22

3.97

-

-

-

1.64;

5. 15

4.46

4.21

4.69

-

4.32

4. 19

-

-

-

2.50

(CD3)2C0

H3

reference)

2

4

HZ

inner

1.57

; 2.33 2.28

5a

6a

CDCl,

(CD3)2C0

5.35

4.05

5.42

4.15

3.87

3.94

3.36

-

-

2.19

1.69

; 1.53

5.25

4.28

3.99

3.98

4.96

3.28

4.07

-

-

2.09

1.51

; 1.42 1. 38

HZ

H3

H4

H5

7

C6D6

5.09

Hl

3.95

3.78

4.16

4.01

3.87

-

-

-

-

1.62 1.26

; 1.48 ; 1.07

8

CDCl,

5.43

4.22

3.84

3.67

4.11

3.90

-

-

-

-

1.72

;

8a

C6D6

5.19

3.82

5.52

4.90

3.66

3.78

-

-

-

i.5;

1.53

; 1. 16

J5,6

J5.6’

J6,6’

9,6

5

10,5

4,0

4.6

14.2

-

-

-

16,o

J1,2

J2,3

J3,4

J4,5

H5’

2

5.2

-

-

3

5,4

-

-

4

3,6

7.0

10.4

5a

4,6

2,0

2,8

5.2

10,O

4,8

12,6

6a

3.8

6,8

6.0

9,2

10.4

6,0

12,4

J1,2

J2.3

7

4.8

4,0

7,4

7,8

8,4

II,2

-

8

4,2

7,2

10,o

10.0

6,~

lo.0

-

8a

3,8

3,2

3,7

6,6

4.9

12.0

I,0

all coupling

constants

J3,4

were

10 6.4

54,5J4,5’J5,5’J2,4

determined

according

to first

order

analysis

1.47

No. 42

with

acetone/H2SG4 Compound

yield.

This

4

by Hughes

gives

is a new xylose-derivative blocking-group

Comparison

of the

proposed products

greater The

off by the

isopropylidene-ring.

action

of

after

the

acid.

diacetate

trans-fused

10 %

The

80 % acetic

S with the corresponding

of compounds

&

isopropylidene-

2. seem

to be

reasonable.

because

The

the resulting

strained. 1

and 8

are

strained

of the six

membered

1

exist

ribo-compound

1. and

9) is not able to cyclize

intermediate

products

on the pyranose

split

gin

off.

will be highly

stability

easily

of conformation

of photolyses

biradical

Although

with a trans-fused

of compound

change

split

The results

is

NMR-data

a remarkable

ring has been

.

l,2,3.4-Di-O-isopropyliden-a-D-xylo-pentopyranose

trans-fused

shows

7)

and Speakman

should

ringsystem

too,

they are formed

ring towards

the seven

in a conformation

by the repelling

forces

because

of

membered

the

ring.

minimising

the &a&

of the hydrogen

atoms

put cis-

10)

syn-cis-arrangement

Literature 1)

P.M.

Collins

2)

P. M.

Collins,

P. Gupta and R.

3)

P. M.

Collins,

P.

4)

K.

5)

A. B.

Heyns

J.D.

and R.

Wood,

6)

B. T.

Lawton,

7)

N. A.

Hughes

8)

M.

9)

D.R.

Morton

10)

J. A.

Mills,

(Reoei~a

inaerzany

Gupta,

J.

Chem. Iyer,

Gupta and R. Neste,

H. W.

Stevens,

Kisio

andP.

W. A.

J.

Iyer,

H. G.

Chem.

Szarek

Hasegawa.

and N. J. Turro, Adv.

7 July

J.

Fletcher, 2,

1965,

(1971)

Commun.

Chem.

Sot.

1261

(1970)

, Perkin

I.

1670

(1972)

Carbohydr.

J..

Chem.

Sot.

2

, 1986 (1957)

525 (1975)

and J. K. N.

and P. R. Speakman,

and A.

Chem.

(C),

in preparation

Diehl,

Auet.

Sot.

Jones,

Carbohvdr.

Garbohvdr.Res.

Carbohvdr. Advances Chem. g,

Res.

g,

Photochem.

4,

Res. g,

456

171 (1965)

95 (1976) 2,

197 (1974)

33 (1955)

1978; reoeivedin UK for plblioation 22 August

1978)

(1969)