Diasteroselective cyclizations with enantiopure malonaldehyde monocycloacetals.
The synthesis of a series of enantiopure malonaldehyde monocycloacetals is described. Treatment of 8b with L-tryptophan methyl ester, 5-methoxytryptamine, and tryptamine, respectively, in the Pictet-Spengler condensation gave the corresponding enantiomerically pure key precursors 1-3 and 17-21 in only two steps. Using a chiral amino-diol successfully realized the kinetic resolution of racemic carbolines 23 and 24.
Bi
Lanrong
L
College of Pharmaceutical Sciences, Peking University, Beijing 100083, People's Republic of China.
Zhao
Ming
M
Wang
Chao
C
Peng
Shiqi
S
Winterfeldt
Ekkehard
E