Abstract
1-Phenyl-2:3,6:7-dibenzosuberyl salts 5 + efficiently catalyze the aldol reaction between silyl enol ethers and benzaldehyde with moderate diastereoselectivity. Crossover experiments with doubly labeled silyl enol ethers, kinetic and stereochemical studies identify 5 + as the catalyst rather than a Lewis acidic R 3 SiX species in this transformation. © 1994.