108
ORGANIC SYNTHESIS—1995
I.E.1-20 Rasset, C. and Vaultier, M., T, 50, 3397; Takayama, H. et al.,
SL, 741.
|Qs0 2
R0 2 C
Ph-Me, 110°C
&
B
''C0 2 R
75-86%
I.E.1-21 Leonard, J. et al., TL, 35, 1071 and JCS(Pl), 2359; Winkler,
J.D., Houk, K.N. et al., JOC, 59, 6879; Chou, S.-S.P. et al., JOC, 59,
2010.
Me0 2 C
Me0 2 C
20a = 79%
20ß=ll%
I.E.1-22 Jackson, R.W. and Shea, K.J., TL, 35, 1317; Martin, S.F. et
al., TL, 35, 691; Uguen, D. et al., TL, 35, 3941, 3945; Fukumoto, K. et
al., 7\50, 10183, 10933.
BnO OBn
OBn
BnO
Ph-Me, 205°C, 18h
O
44%
ORGANIC SYNTHESIS—1995
I.E.1-20 Rasset, C. and Vaultier, M., T, 50, 3397; Takayama, H. et al.,
SL, 741.
|Qs0 2
R0 2 C
Ph-Me, 110°C
&
B
''C0 2 R
75-86%
I.E.1-21 Leonard, J. et al., TL, 35, 1071 and JCS(Pl), 2359; Winkler,
J.D., Houk, K.N. et al., JOC, 59, 6879; Chou, S.-S.P. et al., JOC, 59,
2010.
Me0 2 C
Me0 2 C
20a = 79%
20ß=ll%
I.E.1-22 Jackson, R.W. and Shea, K.J., TL, 35, 1317; Martin, S.F. et
al., TL, 35, 691; Uguen, D. et al., TL, 35, 3941, 3945; Fukumoto, K. et
al., 7\50, 10183, 10933.
BnO OBn
OBn
BnO
Ph-Me, 205°C, 18h
O
44%