SYNTHESIS OF HETEROCYCLES
293
IV.K.3-12 Scheeren, H.W. et al., TL, 35, 4419; Kunieda, T. et al., H,
37, 715; see also: Holmes, A.B. et al., JCS(Pl), 2205; Knight, D.W. et
al., JCS(PI), 1661.
H
OR
2
Plw ^ N
Γ + V
>
s**4>oR
OR'
Ts^
N
T °
R
4
-78°
IV.K.3-13 Hoshino, O. et al., CC, 443.
OR
2
OR
2
80-99%, 0-62% ee
R
PhI(OAc) 2
Ö
39-72%
IV.K-3-14 Palomo, C. et al., JOC, 59, 3123 and TL, 35, 2721 and 2725;
Yoneda, R. et al., TL, 35, 3749; Kurihara, T. et al., CPB, 42, 31; see also:
Bremner, J.B. et al., TL, 35, 2409.
NHBoc
va m-CPBA
O
X - l L
CH 2 C1 2 , -40°
R3
Ö 70-75%
similar examples of oxidative ring expansions