On the homopropargylation of alkylvinylcuprates. A new entrance to the chemistry of juvenile hormones and their analogs.

Letters No. 34, pp 3125 - 3126. OPergamon Press Ltd. 1978. Printed in Great Btitain.

Tetrahedron

ON THE HOMOPROPARGYLATION

TO THE CHEMISTRY

Hans Westmijse

, Henk Kleijn

Department

of vinylheterocuprates

of configuration heterocuprates

1-alkynes

with homopropargylating

compounds

State

, Croesestraat

University

79

,

.

reagents

of alkylvinylcuprates

of such mixed homocuprates

thusfar

l-3

.

like -la-c from

(THF) as a solvent.

towards homopropargylating

, as a smooth homopropargylation

would be an interesting

and their analogs

like 2 has been very troublesome

synthesis

) in more detail

with retention

, the reaction of vinyl-

in many casesl. However

new entrance'tothe

of the vinyl

preparation

of natural

( -vide infra ). In this paper we wish to present

our preliminary

.

results Treatment

of the alkylvinylcuprates

) produced

provided

the desired

-la-c ( cf 4 ) with two mole equivalents

homopropargylated

that the alkylation

was carried 5 phosphite :

(HMPT) and trimethyl

compounds

2 Y-C='C-CH2-CH2-I THF,IIMpT,P(OMe)3,

(2_) c 25OC

:

R'= Ph

b

:

R'= Me

c

:

R’=

c=c

jH 'CH2-CH2-C&-Y

Et/

( 70-90

Me

,R %H2-CH2-

we found that the alkylgroup iodide<

of a number of alkylvinylcuprates

than the vinyl group. We were therefore

yields

%)

Y = H or Me3Si

‘c=c Et/

2 in reasonable

R\

triamide

za-c

a

with methyl

( 70-90 % ),

of hexamethylphosphoric

&a-c

6

of 2 (Y=Hor

2 a-c in good yields

out in the presence

MgBr.LiBr

Recently

AND THEIR ANALOGS.

Peter Vermeer.

in a high yield, using tetrahydrofuran

to study the behaviour

reagents 2 ( Y = H or Me3Si part of these cuprates

HORMONES

ether has been shown to proceed

yields

on the stereospecific

and dialkylcuprates

We decided

and

Chemfstry,

in diethyl

and with satisfactory

Recently4 ,we reported

Me3Si

of Organic

OF JUVENILE

, The Netherlands.

Utrecht

Alkylation

OF ALKYLVINYLCUPRATES.

A NEW ENTRANCE

(N

60 46) from the reaction

3125

very surprised

of -1 with -one

reacted much faster to obtain

equivalent

of -2

.

compounds

Our present 1-alkynes overall

study shows that we now have a method

hormones

: propyne -+h]--+b-+c]-_3c

( e.g.

yield

to compounds

of

and their analogs

Currently

, an extensive

alkylvinylcuprates

study concerning

liaed

phosphite

stirring

30 min to + 25O

,

References 1.

J.F.Normant M.Obayashi

3.

C.Chuit

4.

H.Westmijze

mixture

of THF ( 35 ml ) and HMPT

followed

by stirring

15 min at - 50° two equivalents

during

of the reaction

The yields, which

were in agreement

of 2

mixture

during 6 hours at this temperature.

products

( 5 ml )

; 0.04 mol for R'= Me or (z)-Me(Et)C=CH-(CH,)~

added at - 50°. The temperature

data of the purified

was raised

Subsequently,

are not optima-

with the proposed

structures

in a full paper.

This investigation

was supported

by the Netherlands

aid from the Netherlands

Foundation

Organization

of Chemical

for the Advancement

( ZWO ).

, G.Cahiez

, K.Utimoto

, G.Cahiex

, Tetrahedron

, J.Villieras

, H.J.T.Bos

were omitted

in the presence

, J.Meijer,P.Vermeer

Lett.

71

, 269 ( 1974 ).

, 1805 ( 1977 ).

, Tetrahedron

, P.Vermeer

, 32 , 1675 ( 1976 ).

, Recl.Trav.Chim.Pays-Bas

, the results

of vinylcopper(I)compounds

results

H.Westmijze

, C.Chuit , J.Organometal.Chem., , H.Nozaki

. J.Normant

, J.Meijer

If HMPT and P(OMe), Alkylation better

of

and notes.

2.

6.

4 mol ) in a mixture

( 0.02 mol for R'= Ph

( SON ) with financial

of Pure Research

and other alkylations

:

the reaction

and will be published

Research

for juvenile

hormones.

3 were isolated in the usual manner. 1 were determined by GLC and II-NMR analysis.

Acknowledgement.

5.

of juvenile

products

The spectroscopic ?a-c

the homopropargylation

to the synthesis

of L(O.01

( 0.02 mol ) were cautiously

the alkylated

) in a few steps and in a good

, which are very useful precursors

type zc

is as follows

suspension

we added trimethyl

within

, starting from simple

is in progress.

A typical procedure

at -5OO. After

leads

( cf 3 ).

The results will be applied

To a stirred

at hand which

in diethyl

were disappointing

, 95, 304 ( 1976).

.

ether has also been reported

of HMPT and P(OMej3

.

to give

( cf A 1.

, Recl.Trav.Chim.Pays-Bas

, s

, 194 ( 1977 ).

(Receivedin UK 26 April 1978; accepted for publication 22 June 1978)