Synthesis of C -glycosyl compounds by the addition of glycosyl radicals to olefins

Tetrahedron Letters,Vol.28,No.47,pp Printed in Great Britain

SYNTHESIS

OF C-GLYCOSYL

5853-5856,1987

COMPOUNDS

0040-4039/87 $3.00 + .OO Pergamon Journals Ltd.

BY THE ADDITION

OF GLYCOSYL

RADICALS

TO OLEFINS'

Younosuke

Araki*,

Tadatoshi

Endo,

Masaki

and Yoshiharu Department

of Chemistry,

Faculty

0-okayama,

Tanji,

Jun'ichi

Nagasawa2,

Ishido

of Science,

Meguro-ku,

Tokyo

Tokyo

Institute

of Technology,

152, JAPAN

of 2,3,f+,6-tetra-OAbstract : The Bu3SnH - AIBN induced radical additions acetyl-D-glucopyranosyl derivatives, bearing c+Br (l), U-1 (5), @OCSSMe (77, and p-SePh (8) groups on the anomeric carbon, with olefins such as dimethyl methyl vinyl ketone, dimethyl acetylenedicarboxylate, butyl vinyl maleate, ether, and N-ethylmaleimide were examined for a synthesis of C-glycosyl compounds.

Various

types

ties are found partial

structures

of synthetic synthesis 4 . glycosyl by

of C-glycosyl

in nature3. of many

organic There

have

compounds5.

and

(Bu3SnH)

ethers -

pyranosyl tion',

glycosyl

Dropwise

dimethyl

diastereomeric d) in a good

polar

tions

at 2-position

selectivity effect

lectivity problems

at

reactions

used were

solution

a

induced

(20

eq),

(3),

additions

of equal a lager

a smaller

and

have

restricted

Bu3SnH

of a gluco-

of our investigabeen published 8-10.

to a few

(1.1 eq)

=

glycopyranosyl

simple

2-position

(2a

:

a-anomer

a-anomer

5.3

2b

(2~)"

(2d)"

in

benzene

5853

in

benzene

may

1 : 1,

a (1)

gave

derivatives

of the

a

(2a -

2c

mixture

(21% yield)

and the

Configura-

The high

stereo-

by the anomelow

stereose-

: 2d = 1 : 1.3) causes

to heterocyclic

of

(2a, 2b) (9% yield),

be rationalized 12 The intermediate .

of them

to

bromide

(27% yield).

to be established. : 1)

= ca.

ones

2,3,4,6-tetra-g-acetyl-1,5-

of two,8-anomers

radical

on the case of conversion

eq)

Rechromatography

2d remain

(Or :@

(0.06

product,

Rf-value)

of 2c and

AIBN

yield.

Rf-value)

alco-

hydride

and acrylonitrile.

of

amounts

of

tributyltin

additions

2-glucopyranosylsuccinate

in a 26%

of C-

compounds

In the course

acrylate,

of dimethyl

at I'-position in the

(AIBN)

(68%), and a reduced

(having

(having

of

the

product

synthesis

of C-glycosyl

radical

communication,

addition

methyl

the

as

the interest

in natural

concerning

syntheses

are described.

maleate

2a - d gave the mixture

polar

the

proper-

recognized

of 2,3,4,6-tetra-g-acetyl-a-D-glucopyranosyl

mixture yield

anhydro-D-glucitol

more

In this

biological

also been

blocks

peroxide-induced7

radical

addition

solution

have

and thus they attract

researches

the olefins

such as allyltributyltin,

interesting

building

reported

and

to olefins

however,

the less

many

have

to glycals.

works,

(1.0 es),

products

O(,Cf'-azobisisobutyronitrile

radical

refluxing

with

compounds

as chiral

been

We

similar

In these

ric

natural

chemists

photochemically-induced6

hols

compounds

C-Glycosyl

compounds

no

analogous

5854

to showdomycin. A similar

of 1 with

reaction

methyl

vinyl

(4,)

tetra-g-acetyl-d(-D-glucopyranosyl)-2-butanone yield).

In this

pearance Thus, or

of the starting

it was

added

suggested

to methyl

dimethyl was

recovered

a reaction

pletely

abstracted

clearly

seen

with

butyl

glycosyl

the

(25% yield). use

The of

atom

ether

from

add

as

1

from

of 1 with 1

did not

abstract

On the other

3 quantitatively

(98%

to the olefin

com-

From

behaves

(24%

and the bromide

Bu3Sn

gave

not

Bu3SnH.

radical

atom

to the acetylene.

did

compounds

these

but

results,

a typical

it is

nucleophilic

Thus,

slower

than

of 5 with

(6% yield),

a mixture

reaction

with all

the

of 2c and 2d product

of

5 remained

iodide

smoothly and gave

unchanged from

(5)'" gave a

(45% yield),

ketone

atom

preferably

and

syl radical.

glycosyl

Attempted

after

the

proceeded

3

(6% yild),

no C-glycosyl

(on t.1.c. exami-

5 by Bu3Sn

remained

to be applied

methylvinylketone

and Bu3SnH

occurs

in the reaction

case

of the

was

proved

reaction

from

of 5 with

to be very

Higher

reaction,

mixture

effective

much U.V.

(1 eq.) afforded

3 (ca. 70% yield).

to the AIBN-induced

Bu3SnH

yield

(55% yield)

derivatives,

was

yield due

of

to the

the initial

stage

N-ethylmaleimide, to give

a diaste-

(8)17, were

had

product

to radical

and

phenyl

with

3 (41% yield).

2,3,4,6-tetra-g-acetyl-l-

also

tested

as precursors

of 7 by Bu3SnH

- AIBN

been

for

refluxed

3 was observed,

unchanged

along

2,3,4,6-tetra-g-acetyl-I-O-methylthylthio-

(7)16

reduction

mixture

of the reduced 7 were

and

maleate,

3

N-ethyl-2-(2,3,4,6-tetra-O-acetyl-D-glucopyranosyl)-

seleno-8-D-glucopyranoside

material

more

similarly

4 (53% yield)

of the iodine

thiocarbonyl-fl-D-glucopyranose

formation

vinyl

2d

acetylenedicarboxylate

(30% yield),

3 compared

(6)'5 in a good

other

:

maleate

of 2c and

methyl

of 5, dimethyl

In the

mixture

succinimides

slowly

dimethyl

to give

of the iodide

addition

U.V. irradiation

Two

atom

of Bu Sn to methyl vinyl ketone, but still 3 of Bu3Sn to dimethyl acetylenedicarboxylate.

of all the used

reomeric

5 with Bu3SnH

the abstraction

of the reaction. however,

of

dimethyl

of a solution

the reduced presence

an iodine

than the addition

irradiation a mixture

abstracts

2,3,4,6-tetra-g-acetyl-g(-D-glucopyranosyl

1.0 equivalent

and almost

faster

Bu3Sn

The reaction 2b

the reaction

nation).

that

atom13,

examined. of 2a and

by the

not

vinyl

3

mixture.

reaction

compounds

yield);

added

radical

glycosyl

it is known

a bromine then

mixture

much

(91% recovery completely

the bromine

An attempted

gave no C-glycosyl

and

for the disap-

of the reaction

abstracted

comparably.

the hydrogen

that

either

yield)

was needed

radical.

Because

while

1

intermediate

(40%

of Bu3SnH

on t.1.c. analyses

Bu3Sn

ketone

almost of

the

was

that

quantitatively

yield);

than

1

bromide

vinyl

1 but

from

carbon

equivalents

acetylenedicarboxylate

bromine hand,

four

case,

(10 eq) gave 4-(2,3,4,6-

ketone

system

4.5 hour,

large amounts

(t.1.c. examination).

addition

(10 eq) by the use

reactions.

Thus, The

of 4 equivalents

of the glycoproceeded

very

although

the

of the starting 7 was

reaction of Bu3SnH

decided

of 8 with gave

no C-

5855

LOOMe -I-

[~~~~e

-k

Bu$nH

‘OoMe

>

2a,2b

(1.1 es)

(20 es)

1

crHyi,)u

2-epimer of 2c

+

27

+

x

26

X

AIBN

(0.06 I

+

s+-(

+

Bu+nH

0 (10

eq)

+3

------+

C6H6 ,refb

24 x

( 4 eql

es)

40

%

AIBN

-I-

q

-I0

(10

Bu3SnH

(0.06 eq)

CgHg ,reflw

’

53 x

(1.0 eq)

es)

4+3 6%

5

AC NEt

5+

-I-

E$SnH

+

(1.0 es) (1.0

AC 6 room

temp.

AC w

0 %)

+

AC

es)

3 41 %

6 55 x

COOMe +6 8

COOMe ( 5 es)

AIBN

+

&SnH CL 4

(0.06 C6Hg

,reflw

2 23 %

-/-

3 16 I

-k

8 53 x

5856

glycosyl tion

compounds

with

trace

amounts

recovered slower

8.

than

reduction

of the amount

(53% recovery

From radical

the

Thus,

the addition

abstraction

of dimethyl of Bu3SnH

radicals

the results

maleate

with

bromide

mentioned

to olefins

compounds,

of the

above,

provide

especially

detected PhSe

group

down

that

1 and

a useful

C-glycosyl

by Bu3Sn

by the

and

the C-glycosyl

compound

suitable

by the

compounds

3 (16% yield)

8 is a less

with

is rather

Therefore,

to 5 equivalents

iodide

it was

by t.1.c. along

maleate.

reduced

it is clear

than both

of Bu3SnH,

2 were

up to 4 equivalents,

along

Thus,

of the reac-

to dimethyl

of Bu3Sn

23%yield

yield).

additions

C-glycosyl

compounds

In the case

of 1.1 equivalents

yield.

(20 eq) by the use

of C-glycosyl

obtainedina

of glycosyl

8 in a 76% recovery

maleate

of the amount

increase 2 were

but

dimethyl

and 8

precursor

5.

concluded

methodology heterocycles

that

these

glycosyl

for the synthesis

of

such as C-nucleoside

analogues.

NO 'ES AND REFERENCES

2

6

8

9 10 11

12 13

::

16

17

T. Endo, M. Tanji, Y. Araki, and Y. Ishido, the 50th Annual Meeting of Chem. Sot. Japan, Apr. 1st - 4th, 1985 (Tokyo), Abstr. p. 962. Present address : Research Institute for Polymers and Textiles, Yatabehigashi, Tsukuba, Ibaraki 305, Japan. S. Hanessian and A. G. Pernet , c. Carbohydr. Chem. Biochem., 33, 111 --188 (1976). "Total Synthesis of Natural Products : The 'Chiron' ApS. Hanessian, proach", Pergamon Press, Oxford (1983). Recent papers : S. Hanessian, M. Martin, and R. C. Desai, J. Chem. Sot., Chem. Commun., 926 - 927 (1986) ; P. Lesimple, J.-M. Beau, G. Jaurand, and -P. Sinag, Tetrahedron Lett 27, 6201 - 6204 (1986) ; T. L. Underiner and H. L. Goering , J. Org. __*, Chem -*’ 52, 897 - 900 (1987). Y. Araki, K. Senna, K. Matsuura, and Y. Ishido, Carbohydr. Res., 64, 109 117 (1978). T. Endo, Y. Araki, and Y. Ishido, the 48th Annual Meeting of Chem. Sot. Japan, Aug. 27th - 3Oth, 1983 (Sapporo), Abstr. p. 669. G. E. Keck and J. B. Yates, J. Am. GE. SE., 104, 5829 - 5831 (1982) ; G. E. Keck, E. J. Enholm, and D. F. Kachensky, Tetrahedron Et., 25, 1867 - 1870 (1984). B. Giese and J. Dupuis, Angew. Chhm. --Int. Ed. Eng., 22, 622 - 623 (1983). R. M. Adlington, J. E. Baldwin, A. Basak, and R. P. Kozyrod, J. --Chem. @., Chem. Commun., 944 - 945 (1983). The structures of these compounds were confirmed by their ir and nmr soectra. and bv their micro-elemental analvses. B: Giese and Jr Dupuis, Tetrahedron Lett.,"25, 1349 - 1352 (1984). B. Giese, "Radicals in Organic Synthesis : Formation of Carbon - Carbon Bonds". Pereamon Press. Oxford (1986). J. Thiem and B. Meyer,'Chem.&.,'l<3, 3075 - 3085 (1980). -Several attempts to isolate pure stereoisomers from the mixture were unsuccessful. However, its nmr spectrum and micro-elemental analysis datum agree well with the desired C-glycosyl structures. This compound was synthesized from 2,3,4,6-tetra-g-acetyl-D-glucopyranose by the application of Gross's method with a slight modificaton : P. D. Cesare and B. Gross, Synthesis, 714 - 715 (1980). W. A. Bonner and A. Robinson, J. -Am. --Chem. =., 72, 354 - 356 (1950). (Received

in Japan

25 June

1987)