Auxiliary induced asymmetric Michael-aldol reaction under kinetic and thermodynamic conditions
摘要:
Asymmetric intramolecular Michael-aldol reaction of (-)-phenylmenthyl enoates 1 affords tricyclic cyclobutanes 2 in excellent diastereoselectivity. It is made clear that Michael-aldol reaction is reversible under conditions using trimethylsilyl iodide (TMSI) in the presence of hexamethyldisilazane (HMDS) at ambient temperature. The difference of stereoselectivity under kinetic or thermodynamic conditions are reported. (C) 2000 Elsevier Science Ltd. Ail rights reserved.