Two-step synthesis of allylic silicon derivatives from enones

TWO-STEP SYNTHESIS @F ALLYLIC SILICON DERIVATIVES FROMENONES DA”13

PANJIY-SZEKERES,

GCRARD

DtLtRIS,

JEAN-PAUL

PICARD: JEAN-PAUL

PILLOT

AND RAYMOND

CAMS

Laboratoire de Chimie Organique et Laboratoire des CornposEs Organiques du Silicium et de l'Etain, associ6 au Centre Kintional de la Kecherche Scientifique (L.A. no 35), FacultG des Sciences, F-37405 TAT,EL'CF.

The use of allylsilanes years(i)(2)

and the importance Since many

synthetized (3)(4)

However tively

Reductive compounds

through

ketones

of allylic

group

rapidly

from terpenic

at an allylic

60

position

in rela-

challenge.

readily

accessible from ethylenic to such allylsilanes (5) . We now wish to

propenyl

the corresponding

compounds

vinylic

of the type 3 and 4, 2 (6) following ’ -

dithiolanncs

+

the

IISWSH NeOH

-

-2

SiEle3

Ye.,SiCl/Li/THP

msire +

-2 c -5°C

'Ie3SiA---_diMe3

3

-4

-3

The results

submitted

solvent

-2 were

to reductive

always

silylation

formed without

almost

quantitatively

further

purirication

from the enones I_, and after removal

of the

methanol. The formation,

real problem instance, isomer,

in the Table.

are summarized

The dithiolannes

with

allylsilanes

:

scheme

were

in recent

and, for instance,

is an interesting

thioethers,

of his-silyl

on this field

and nitriles

products,

led us easily

of a variety

quite

has been established.

our attention

as are natural

through

has developed

of a trialkylsilyl

an ene-reaction,

from enones I,

focused

p-mcnthenyl

silylation

the synthesis

starting

we have

or A-1,7

substrates,

synthesis

of such intermediates

the introduction

sensitive

report

years,

e-pinenyl

in organic

since

cases,

the less stable

on treatment

-3 and -4 have

allylic

in most

with

of a mixture

isomer

2 and 4 is no

can be converted into the more stable one, for (Ii) Whichever is the more stable fluoride .

tetrabutylammonium

at least one Si-C allylic

transposition,

of the two repin-isomers

as examplified

bond which

can be cleaved

in the following. 4267

by electrophiles

-TABLE-

Yn the (A~OH)~P’F~ at vinylsilane

presence of a half-equivalent -25OC (15) , monoprotodesi lylation

5 (from

of

the

acetic:

occured,

-3) or the corresponding

allylsilnne

I /2

acid/boron

yielding

either

6 (from

_

trifluoride

it)

-

the

complex

corresponding

:

(k0~) ,p~~

5b

Q --{l

Xe Si 3

\

.--

i ?le

-4c

this

3

When -ira and -6a were reacted 3.5.j.-trimethvlcvclohexene

respectively (16)

complex,

with

OIIP or

was obtained

one half

nf

an equivalent

of

:

4a 6a

Similarly,

3.7-dimethyl

octa

1.6-diene

was obtained

upon

treatment

of

3f with

one

-

equivalent

of

the

complex

: 1 (AcOH) ,BF3

We also as

3-silyl

showed

prnpenes,

1.0 Lhe introduced

that

because carbonyl

-4d

1 .3-bis-silyl of

group

the lability (17) Pllr

propenes of

the

iIISt;,,,~‘e !

i behave, ._ remaining

towards silyl

acplation

group

on the

reactions, C-adjacent

4??!l

These suitable

preliminary

The fllrcher natural

results

for the three-steps

products

demonstrnLr

current

investigation

E.W. COLVIK, Chem.Soc.Rev., (1978) Ii. 'T.H. CHAX and I. FLEMlE;G, Synthesis, (1979)

2-

R. CAI.AS, "Thirty in press.

3-

J.-P.

4-

G. DELERIS,

Thgse

5-

G. DELEKIS,

J. KOWALSKI,

6-

The synthesis

in

Organosilicon

sef for

Bordeaux,

and R. CALAS,

dithiolannes

a- J.L. GRAS, R. MAURIK and V. BERTRAND, b- J.R. WILLIAMS

d- U. SCHURERT,

TRllESUALC, K.G. Synthesis,

B.E. ?:cCARPy,

8-

.J.Org.Chem., 44 (lY79)

3387.

Tetrahedron

directly

cram enones

I,eft., (1977) 4211. has been reported

;

Tetrahedron

Synthesis,

CRlm

Lett.,

(1969)

3533.

(1974) 32.

and S.L. NESBITT,

J.Amer.Chem.Soc.,

-99(1977)5009.

J.Org.Chem.,

-44(1979)

656.

Ft.:.. yzV?KE%Tr'H and S.C. ROOTS, J.Amer.Chem,Soc.,

IO?

352.

g- R.I.. fi\RKEZICH , W.E. WILLY, 7-

J.Orga1~~1111~Lal.Chern., LOO(l980)

(1978) 364.

and S.J. HOBBS,

1m X . S . JOHXSON, (1980)

2nd G.M. SARKISIAK,

L.K.

e- U.K. MORTON

of

:

instnncc

c- L). EVX?S,

to the synthesis

(1979) 66.

J. DUKOGUES

of sonic vinylir

is very

761.

Chemistry",

PII.f.O'I', G. DEI.t:LITS, J. DlX:IX;I'CSand K. CALAS, d'Etat,

we propose

skeletons.

in our 1aboraLories.

1 -

Years

that the melhod

of terpenic

cri this nletllodand its applications

development

is under

clearly

furlctionnalisation

The procedure

described

H.E. McChRRY

and V.S. JOHNSOIX, ibid., -95 (1973) 4414.

in reference

6b has been used. 19 SL NXR and IR) entirely consistent All new productsprescnt spectroscopic data ('H, 13c , prfparative Gc UT with the ;issigned strucrurc ; they h;lvcsbeen isolated by distillation, HI'LC, except the dithiolanncs _2 which were pure enought after evaporation of the solvant.

J. Org. Chem., -41 (1976) 611 and references therein. IO - We whislr to thank I'. 'I'EISSEIRE, Scientific Director nf the Sorigt$ ROURE-H~:I(T~ND-I)IIPOUT (Grasse, France) for providing us with this sample. 9-

R.X. MOSS

and D.J.

SMUDIX,

II - Prepared by oxidation of 3-methyl 2-buten l-01 with pyridinium E.J. COREY and J.GJ. SUGGS, 'l'ctrahedron L<>tt., (1975) 2647. I? - The corresponding dithiane has been reported and M. IKEDA, Synthesis, (1973) 312. 13 - The sterr%ochemi.stry at the double pwscnt time. 14 -

A. ~IOSOMI,A. SHIRAHATA

I5 - I. FLEMING

Ih - K.O. HUTCHIXS,

(:.A. XILEWSKI

17 - A.Tt7.P.JARVTE,

Organometal,

Synthesis,

Chem.Lett.,

(1978)

Rev.

with

certainty

zit the

901.

(1979) 445.

and B.E. ?~~RYANoFF, J. tier. Chem.

:

: Y. TAYJRA, K. SUMOTO, S. FUJII, H. SAT0

bond has not been established

and H. SAKURAI,

and I. PETERSOX,

chlorochromate

(A), -6 (1970)

153.

them,

SW.,

-95 (1973)

3662.