Axial Allylation on the diosphenol claisen rearrangement

Tetrahedron Letters,Vol.24,No.l,pp Printed in Great Britain

AXIAL ALLYLATION

3-6,1983

ON THE DIOSPHENOL

0040-4039/83/010003-04$03.( 01983 Pergamon Press Ltd.

CLAISEN

REARRANGEMENT

A.A. Ponaras* Departments The Catholic

of Chemistry

University

Washington,

D.C.

of America 20064

and The University

of Maryland

Baltimore,

A 5:I preference

ABSTRACT: Claisen

rearrangement

of the Claisen

stereocontrol, allyl-vinyl received

ethers contained 4

question

allylation diosphenol

1.

is shown in the ally1 ether 1.

in stereoselective

of a chair transition Another

for axial bond formation

within

conformationally-rigid

Since diosphenol

for cycloalkenyl-ally1

this stereochemical

consequences

a preference

little attention.

substrates

rearrangement

from a C-O bond to a C-C bond.3

namely

County

21228

for axial -vs. equatorial

are based on the stereochemical transfer

MD

of the conformationally-rigid

Most applications

chirality

Baltimore

ally1 ethers

ether Claisen

synthesis

state2 or on

potential

source of

in rearrangement cyclohexane

systems,

are readily

accessible

rearrangements5

t-Bu

+

R la

lb

*Address

R=H R=CH,

correspondence

to the author

at the Catholic

University

has

we have investigated

in the system 1:

t-Bu

of

of America.

4

d6

and k6

in 65% yield

Heating produced, tially

by the method

a 11

and h6

+0.06

acid for fifteen Selective

in pyridine

&

(oxime m.p. 144-148',

This assignment

producing,

reduction

solvent

iodide

shifts8

b R=CH,

assigned

essen-

the strucgroups

as follows.

acetate

bond produced

which was treated in boiling

acetic

product

the known lo 3

142').

t-Bu

t-Bu

hours

having

from 2a, the deoxygenated

double

2:

of their methyl

m.p. 121-124°,

and lithium

in 70% yield

m.p.

(117') for twelve

was confirmed

to a6,

of the conjugated

reportedloa

synthesized

of two diosphenols

They were tentatively

was converted

each of lithium

minutes

at reflux

an 84:16 mixture

in CDC13.

resp.).

diosphenol

k6, m.p. 81.5-83.5',

from 4-t-butyl-Z-methylcyclohexanone -

on the basis of the benzene

with three equivalents

8a '*' -*

of h

yield,

NM? spectra

and +0.22,

The major

from diosphenol

of Wallach7

solution

in 89% isolated

identical

tures a6 (A=

were prepared

t-Bu

Li/NHS THF-H20

t-Bu

t-Bu

HO

R

Rearrangement in pyridine

of Q

was slower than that of &

an 85% isolated

yield

of diosphenols

but after forty-five

c6

and a6

hours reflux

in the ratio of 83:17 was

isomer &, m.p. 42-47', was converted to a6, m.p. 135.5-138.5', 10 (oxime m.p. 150-151°, reportedloa m.p. 150-151'). and then, -=* via 8b 6 to 3 The major

produced.

Heating & can detect

in pyridine

ment is irreversible reaction

conditions.

conversion

for sixty hours produced no detectable & (VPC analysis 5b once again that the diosphenol Claisen rearrange-


and, furthermore, Additionally,

that enolization

analysis

to g

does not occur under the

of the rearrangement

products

at low

showed 2 and 2 in the ratio of 5:1, and thus this is the true kinetic

It is noteworthy axial attachment

that this Claisen

of ally1 or methallyl

sodium t-amylate/benzene We are presently

ACKNOWLEDGEMENT:

whereby

exploiting

rearrangement

shows a greater

preference

of 2 with alkyl halide/ 10a a 4:3 ratio of 2 and its epimer are produced.

this enhanced

I thank the National

stereoselectivity

Institutes

in sesquiterpene

of ,Health for support

synthesis.

of this work.

1

For reviews of the Claisen rearrangement see a. Rhoads, S.J.; Rawlins, N.R. Org. Reactions 1975 -)=)-.-) b. Ziegler, F.E. Act. Chem. Res., 1977, lo, 227. c. Bennett, G.B. Synthesis, u, 589.

22

1.

2

Boat transition states are sometimes important: a. Cave, R.J.; Lythgoe, B.; Metcalfe, D.A.; Waterhouse, I. J. Chem. Sot., Perkin Trans. 1, 1977, 1218. b. Ireland, R.E.; Vevert, J.P. J. Org. Chem., 1980, 45, 4259. c. Bartlett, P.A.; Pizzo, C.F. J. Org. Chem., 1981, 4&, 3896. d. Ziegler, F.E.; Thottathil, J.K. Tetrahedron Lett., 1982, 23, 3531.

4

Inter alia: a. Burgstahler, A.W.; Nordin, I.C. J. Amer. Chem. Sot., 1961, 83, 198. b. Hill, R.K.; Edwards, A.G. Tetrahedron Lett., 1964, 3239. c. Bolton, I.J.; Harrison, R.G.; Lythgoe, B. J. Chem. Sot. C, 1971, 2950. d. Stork, G.; Raucher, S. J. Amer. Chem. Sot., 1976, 2, 1583. Almost all examples of Claisen rearrangement involving l-substituted cyclohexenes have steric bias or are enmeshed in conformationally-mobile frameworks. In situ formation and cracking of 4-&-butylcyclohexanone ally1 ketals gives, initially,a preference for axial allylation, but product equilibration under the reaction conditions has prevented an accurate measurement of the stereoselectivity:

a. Fleming, I.; Kemp-Jones, A.V.; Long, W.E.; Thomas, E.J. J. Chem. Sot., Perkin Trans. 2, 1976 7. b. Howard, J.L., Dissertation, Harvardiniversity, Cambridge, 5

for

than does alkylation

REFERENCES

3

ratio.

Tetrahedron Lett., 1980 a. Ponaras, A.A. b. Dauben, W.G.; Ponaras, A.A.; Chollet,A.

Mass.,

Sept. 1981.

4803. J. Org. Chem., 1980, 45, 4413.

6

6A11 new compounds correct

gave satisfactory

exact mass.

0.92,

NMR,

IR and mass spectra as well as the

The 90 MHz NMR spectra

(CDC13) are summarized

s, 9H; 1.7, m, 1H; 1.91, s, 3H; 2.0-2.8,

4.9-5.5, U.92,

m, 2H; 5.5-6.3,

m, 4H; 4.32, d, J=6, 2H;

m, 1H.

s, 9H; 1.7, m, 1H; 1.80, s, 3H; 1.93, s, 3H; 2.0-2.8,

4.16, s, 2H; 4.89, 0.94,

below.

m, 4H;

"d", J=5, 2H.

s, 9H; 1.13,

s, 3H; 1.3-2.0,

m, 2H; 2.23, d, J=7, 2H; 2.4, m, 1H;

5.00, m, 1H; 5.18,

s, 1H; 5.5-6.0,

m, 1H; 6.18, t, J=2, 1H.

0.90,

s, 9H; 1.16, s, 3H; 1.3-2.0,

2.41, ddd, J=2,2,9,

m, 2H; 1.71, narr m, 1H; 2.20,

1H; 4.66, br. s,

s, 2H;

1H; 4.88, narr m, 1H; 6.07, t, J=2, 1H.

same as &I. same as 2. 0.88,

s, 9H; 1.84, s, 3H; 1.8-2.7,

0.98,

s, 9H;

5.4-6.1,

s, 1H; 7.23, s, 5H.

6.51,

s, 1H; 7.22, s, 5H.

0.96,

s, 9H; 1.08, s, 3H; 1.2-1.9,

5.15,

s,

0.96,

s, 9H; 1.10, s, 3H; 1.2-1.9,

4.68,

s,

8Bhacca,

1916

N.S.; Williams,

of dialkyl

chloride,

4-phenylpiperidine reagent 10

m, 3H; 2.18, d, J=7, 2H; 4.93, m, 1H;

m, 3H; 1.71, s, 3H; 2.20, s, 2H;

296.

D.H. "Applications

thiocarbamates of the enolic

of this reaction

carbothioyl

414

from the Steroid Field,"

method for replacement details

to ensure

in a future

m.p. 90-91.5',

and thiophosgene) highly crystalline

of NMR Spectroscopy

Holden-Day,

of diosphenols hydroxyl

in

USA

as the dialkylthiocarbamyl

derivatives.

N.J.; Conia, J.M. Tetrahedron 13

We will report

4-Phenyl-l-piperidine-

(prepared from commercially-available was chosen

September 1982)

Chemistry,

1964, pp. 165-170.

with iodide ion is a general

by hydrogen.

publication.

in Organic

San Francisco,

1966 a. Conia, J.M.; Briet, P. Bull. Sot. Chim. Fr. -3 b. Dawes, K; Turro,

(Received

m, 4H;

1H; 4.88, narr m, 1H; 5.96, dd, J=3,10, 1H; 6.90, ddd, J=2,2,10, 1H.

0. _)-)-) Annalen

Treatment

m, 12H; 1.80, s, 3H; 4.6-5.4,

1H; 5.4-6.1,m, 1H; 5.90, dd, J=3,10, 1H; 6.89, ddd, J=2,2,10, 1H.

Illustrations 9

1H.

1.11, s, 3H; 1.4-2.1, m, 6H; 2.1-3.4, m, 6H; 4.6-5.4, m, 4H;

m, 1H; 6.48,

1.00, s, 9H; 1.13, s, 3H; 1.3-3.5,

'Wallach,

m, 5H; 5.96, s,

3881, 3888.

Lett., u,

1377.

the