SYNTHESIS OF HETEROCYCLES
249
IV.E-18 Swenton, J.S. et al., TL, 35, 7529; see also: Harayama, T. et
al., CPB, 42, 1550.
R i
HO
^ . O C H 3
S=CR!
XX
R
SPh
R
anodic oxidation
IV.E-19 Knight, D.W. et al., SL, 253.
OCH,
35-88%
NBS or NIS
38-92%
X = Br, I R'i
IV.E-20 Dzhemilev, U.M. and Ibragimov, A.G., JOMC, 466, 1; see
also: Fagan, P.J., Nugent, W.A. and Calabrese, J.C, JACS, 116, 1880.
Et
Se or S 8
PhH, 80°
cT"
X = Se, S
60-85%
IV.E-21 Freeman, F. et al., JOC, 59, 4350; see also: Chambers, R.D. et
al., JCS(Pl), 3119.
Ph—CSC—C=C—Ph
Ar*-CH 2 SH
CH 2 Ph
- X k
P h - ^ S ^ A r ·
54-66%