Title: Highly Efficient and Environmentally Benign Catalytic Enamine Reaction of Unmodified Aldehydes and its Application to Terpenoid Syntheses
VOLUME: 1 ISSUE: 2
Author(s):Hisahiro Hagiwara
Affiliation:Graduate School of Science and Technology, Niigata University, 8050, 2-nocho, Ikarashi, Niigata 950-2181, Japan.
Keywords:diethylaminotrimethylsilane, conjugate addition, cyclopropanation, aldol condensation
Abstract: Unmodified aldehydes add in 1,4-manner to electron deficient olefins in the presence of a catalytic amount of diethylaminotrimethylsilane. Reaction with methyl α- haloacrylates provided formylcyclopropanecarboxylates by domino conjugate addition-alkylation. Aldol condensation afforded unsaturated aldehydes. The reaction was revealed to proceed via catalytic enamine pathway. Total syntheses of several bisabolane type sesquiterpenoids have been accomplished according to this protocol.
