Intramolecular ring cleavage of chiral terpenoid-derived oxazinone via asymmetric anti-aldol reaction: Unexpected entry to a N-substituted tetrahydro-1,3-oxazine-2,4-dione derivative
摘要:
In the presence of excess Bu2BOTf to promote anti-selectivity, an asymmetric aldol reaction with a homochiral terpenoid-derived 1,3-oxazin-2-one as the chiral control element results unexpectedly in ring cleavage by an intramolecular process to form a N-substituted tetrahydro-1,3-oxazine-2,4-dione in virtually quantitative yield. (C) 1997 Elsevier Science Ltd.