SYNTHESIS OF HETEROCYCLES
253
IV.F-6 Katritzky, A.R. et al., T, 50, 12571; Pandey, G. et al., TL, 35,
7439; Torii, S. et al, SL, 217.
Me 3 SiH 2 C. x CH 2 Bt
toluene, A >
R,
£ 0 2 E t
RL
J C O 2
Q
similarly for other azomethine ylids
R
71-90%
IV.F-7 Gamer, P. and Dogan, O., JOC, 59, 4; Heathcock, C.H. et al., TL,
35, 3651; Tanaka, K. et al, BCJ, 67, 589; Matsumoto, K. and Lown, J.W.,
CJC, 72, 2108; Leroy, J. and Wakselman, C , TL, 35, 8605; LaPorta, P. et
al., 5, 287.
DMAD
^ N N ^ c O X *
Me0 2 C
C0 2 Me
82%, 11:1 selectivity
similar inter- and intramolecular cycloadditions using alkenes
IV.F-8 Deng, W. and Overman, L.E., JACS, 116, 11241.
nC 9 Hi 9 CHO
B
If
NH 2
CSA
via [3,3] sigmatropic rearrangement
C9H19
H 61%