6
ORGANIC SYNTHESIS—1995
I.A.2-3 North, M. et al., TL, 35, 6335.
ZHN'
,C0 2 Me
1) 2 LHMDS
►
2)E
+
COj'Bu
,C0 2 Me
C0 2 'Bu
50-80%
I.A.2-4 Royer, J. et al., JOC, 59, 3769; Smith, A.B., Ill Hirschmann, R.
et al., TL, 35, 8977; see also: Kim, D. et al., TL, 35, 9211.
1) LDA,
2) RX
7:3 mixture
62-79%, 93-97% de
I.A.2-5 Sakai, K. et al., T, 50, 3315.
R-X
> y C 0 2 M e
LDA, HMPA
84-96%