Abstract
The alkaloids (I) and (II) are used to catalyze the reaction of nitromethane with α-ketoesters. In both cases, the corresponding products (with opposite absolute stereochemistry) are formed in excellent yields and enantioselectivities. (Va) and (IXa) are applied for the preparation of (X) and (XI), key intermediates in the synthesis of antitumor and anti-HIV natural products.