Asymmetric aldol reaction of acetaldehyde and isatin derivatives for the total syntheses of ent-convolutamydine E and CPC-1 and a half fragment of madindoline A and B.

The asymmetric aldol reaction of isatin derivatives and acetaldehyde has been developed using 4-hydroxydiarylprolinol as a catalyst, affording the aldol products with high enantioselectivity, these products being key intermediates in the synthesis of 3-hydroxyindole alkaloids. Short syntheses of ent-convolutamydine E and CPC-1 and a half fragment of madindoline A and B have been accomplished.