The Baylis-Hillman Reaction with Chiral (alpha)-Amino Aldehydes under Racemization-Free Conditions

The Baylis-Hillman reaction with chiral (alpha)-amino aldehydes has been revisited. The reaction carried out under the influence of ultrasound avoids the aldehyde racemization almost completely, providing useful chiral substrates which can be used as starting materials for the synthesis of natural products. To demonstrate the synthetic applicability of these adducts, the easy preparation of a bicyclic lactam with an indolizidinic skeleton was accomplished.