Total synthesis of (.+-.)-pleurotin and (.+ ... - ACS Publications

J . Am. Chem. SOC.1988, 110, 1634-1635

1634

Table I. Tin Hydride Induced Cyclization of Oxime Ethers

substrate (1) entry 1 2 3 4 5 6 7 8 9 10 11 12 13

R’ c-C6H

1I

c-C6H11 c-C6H I I

c-C6Hl

I

p-MeOPh p-MeOPh BnOCH2 ZSiOCHi c-C6H,

I

c-C,H,, c-C6Hll

p-MeOPh p-MeOPh

product ratiosc

R2

R3

R4

Xa

n

solventb (M)

H H H Me H H H H H H Me H H

H H Me H H H H H H

Bn Bn Bn Bn Bn Bn Bn Me Bn Bn Bn Bn Bn

PTC PTC PTC Br PTC PTC PTC PTC PTC PTC Br PTC PTC

1

B (0.01) B (0.1) T (0.01) B (0.001) B (0.002) B (0.05) T (0.2) T (0.2) T (0.01) B (0,001) B (0.002) B (0.05) B (0.001)

Me H H H

1 1 1 1 1 1 1

2 2 2 2 2

2c

+ 2t/3

87/13 8911 1 73/27 >98/2 4819‘ 571 18’ 83/17 88/12 73/27 98/2 50/50 5 1/49 33/67

84 89 74 63 42 48 59 67 71

33/67