Acetaldehyde, directed condensation with benzophenone

However, even in the singularly smoothly operating directed aldol condensation with aromatic ketones, there is no such thing as perfection. In order to determine the influence of inductive and steric effects on the new process, the Schiff bases of a-substituted acetaldehydes were metallated under the standard conditions with lithium diisopropylamide, and the aldimine adducts with benzophenone were isolated. Table 1 shows the measured yields. 

---