Regioreversed reactions of trimethylsilyl or phenylselenyl allylic carbanion with carbonyl compounds via allylic aluminum “ate” complexes

Tetrahedron Letters,Vo1.23,No.44,pp Printed in Great Britain

4597-4600,1982

0040-4039/82/444597-04$03.00/O 01982 Pergamon Press Ltd.

REGIOREVERSED REACTIONSOF TRIMETHYLSILYL OR PHENYLSELENYL ALLYLICCAR3ANION WITH CARBONYLCOMPOUNDSVIA ALLYLICALUMINUM"ATE" COMPLEXES

Yoshinori

Yamamoto*,

Department Kyoto

Summary

reacts

allylic

either

lithio-anion

with

Saito,

Faculty

and Kazuhiro

of Science,

carbonyl

"ate" complexes

carbanion

exclusively

react with

y-selectivity

compounds

at the

1

or ally1

at the y-position

phenyl

predominantly

selenide

2

usually

(1 = and 2).

1‘

;c=o

of

the a-selectivity

carbanions

regardless

(eq l), and previously

substituted

selectivity

allylic

via allylic

x~-------_,

reported

carbanions

aluminum

of the substituent,

We now wish

to report

and selenyl

The results

of oxygen

(X = 0 and S) can be controlled

and

to the cz-

ate complexes. 3

X = RS, RSCO), RS(02>,RO,

RCHO that

X, of allylic

that the regiochemistry

RSE, R2N, R3S1, R2B, I mI (1)

OH

to silyl

and

1 can be converted to the a-selectivity by changing the = 1 to magnesium (II). We have been seeking a general method for

counterion

sulfur

University

or predominantly.

of allyltrimethylsilane compounds

carbonyl

T

creating

Kyoto

of trimethylsilyl

;c=o The

Maruyama*

606, Japan

phenylselenyl

The

of Chemistry,

Triethylaluminum

a-position

Yoshikazu

this aluminum

substituted

are summarized

allylic in Table 4597

ate complex carbanions 1.

method

is also applicable

(eq 2).

Evidently,

the aluminum

ate

4598

Table

1. Regioreversed

Ally1

Carbanion

Carbonyl

=I

CH3CH2CHO

reactions

via allylic

Compound

Additive

(CH3)2CHCHO

C6H5CH0

C6H5-i-CH3 0 =2

aluminum

"ate" complexesa a-Attack

(%)

y-Attack

Et3Al

94

6

None

10

90

Et3Al

85

15

None

10

90

Et3Al

71

29

None

17

83

Et3A1

24

76

None

CH3CH2CH0

-100

Et3A1

-100

None KH3)2CHCH0

12

Et3A1

88

-100

None C6H5CH0

C6HG-CH3 0 a All reactions text.

The products

comparison without

with

around

carried were

authentic

additives.

analysis. high,

were

identified

78

22

None

18

82

Et3A1

64

36

None

15b

85b

by NMR,

materials.

The u/v ratio was

-100

Et3A1

out on a l-mm01

"None"

scale with

the same procedure

IR, and mass indicates

determined

spectroscopy,

the normal

by NMR spectra

The total yields of ate complex reactions b 75-85 %. The data from H. J. Reich,

and normal J. Org.

in the

or

reaction or GLPC reactions

Chem.,

were

40, 2570

(1975).

x*

-. ET3AL*

X = ME+I,

PhsE

(%)

(2)

4599

complex

method

well

for aldehydes,

and benzaldehyde.

hyde, nantly

of 1 even when = regioselectivity is achieved

acetophenone,

results

indicate

bulkiness

of both

The general silane

(0.14 ml,

in dry THF under

the degree that

carbonyl

1 mmol)

added

(l.5 % in hexane,

hexane

few minutes. quenched

aqueous

To a solution

was

NH4C1

solution

stereoselective Diparopsis

solution

to warm

(0.2 ml,

added

upon the steric

of ally1

(0.7 M, 1 mmol)

was

Similar

procedure

at O'C under

at -78'C.

After

and then

to room temperature

30 min,

for 2. =

(1 ml) was added phenyl

Et3A1

an electrophile

afforded

our attention

to an application

of the present

in hexane

was

and then quenched

acetate,

added. with

the desired

product.

method

a pheromone

to the

of

(eq 3).

1) Et3A1

2 E=

> 2, Aco-/,HO

k \\OAc

a

and then

hllyl

N2'

in

after

was used

The usual work-up

of 9.11-dodecadiene-l-y1

Et3A1 added

temperature,

in dry THF

1 mmol)

at -78°C

for 30 min.

to room

1.4 mmol)

trimethyl-

(0.15 ml,

and an electrophile

to warm

These

at O'C.

synthesis

castanea4

was

at -3O'C

at OOC.

at this temperature,

allowed

turned

added,

(1.4 M, 1.4 mmol)

1 mmol)

added

was

We next

was

in hexane

was kept

was allowed

NH4C1

in hexane

(0.14 ml,

The mixture aqueous

1 mmol)

of diisopropylamine

n-butyllithium

(1.4 mm011

temperature

The mixture

with

selenide

set-butyllithium

of 2 =

(X).

and NNN'N'-tetramethylethylenediamine

The reaction

N2.

in the reaction

depends

To a solution

predomiAlthough

is not so high.

and heterosubstituents

is as follows.

reacts

is used.

ate complex

of regioselectivity

compounds

procedure

triethylaluminum by using

iso-butyralde-

acetophenone

however,

of the selectivity

the reversal

(1 ml) was

such as propionaldehyde,

Unfortunately,

at the y-position

"reversed" with

works

(3)

4600

Treatment

of triethylaluminum

produced

The ratio

via p-toluenesulfonic

of E/Z was

References

"Silicon

2) D. L. J. Clive, 3) Y. Yamamoto,

in 70 % yield. diene 7 in 77 % yield.

acid gave the desired

, 4669

5) 1H NMR

in Organic cited

Synthesis,"

34, 1049

R. Lester,

6 1.10-l-76

(bm, 14H),

1.96

ratio

and 16 Hz, lH),

is not determined

W. Dumont,

(CC14, TMS)

A. Krief,

7.20

6 1.20-1.90

of E/Z was

L. M. McDonough,

Interestingly,

(1977).

by GLPC which

D. A. George,

Since

the acid mediated

precursor

is 84/16. will

in a trans

2.00

Tetrahedron

22 July

(d-d, J=lO

and threo)

and 2 Hz,

in this

adduct,

(1976).

(s, 3H), 2.00-2.24 spectrum,

J. Chromat. occurs

m/e

(M+). epoxide

with m-chloroperbenzoic

Sci.,

8, 158

(1970).

at the level of 88 to 93 %

C. A. Henrick, B-elimination

in due course.

225

(m, 2H),

of the corresponding

Tetrahedron,

control

33, 1845

of 8-hydroxy-phenylselenyl

fashion, 6 the threo/erythro

1982)

(m, 2H),

(m, 2H).

1385

was prepared

The stereochemical

be published

in Japan

Lett.,

analysis

sex attraction

and not at 100 % E isomer;

proceeds

(Received

(1980).

(s, 3H), 2.00-2.44

(erythro

(m, 5H); mass

acetate

the maximum

compounds

carbanions

therein.

at this stage.

(bm, 12H),

determined

of 9.11-dodecadiene-l-y1

E isomer,

cited

R. G. Poppi,

(m, 3H), 7.48

Tetrahedron

(t, J=6 Hz, 2H), 4.80-6.54

8) The ratio

1981,

45, 195

(t, J=6 Hz, 2H), 4.92

there may be two diastereoisomers

6) J. Remion,

London

(1973).

(t-d, J=lO

the exact

7) 1H NMR

J. Orq. Chem.,

R. A. Cole,

(t-d, J=8 and 2 Hz, lH), 3.98

Although

(1978) and references

K. Maruyama,

P. S. Beever,

(CC14, TMS)

2H), 5.76

Butterworths,

therein.

Tetrahedron,

H. Yatagai,

4) B. F. Nesbitt,

acid;

acetate

84/16.8

p. 118 and references

4.02

9-oxonon-l-y1

and Notes

1) E. W. Colvin,

3.54

of 2 with

12-acetoxy-4-hydroxy-3-phenylseleno-l-dodecene5

Elimination6

/Lett

ate complex

based

ratio

of the

on heterosubstituted