N,O-Heterocycles as synthetic intermediates

Abstract

Abstract Hydroxylamines can be cyclized under various conditions according to the nature of the unsaturation in the N -substituent. Both isoxazolidines and tetrahydrooxazines can be formed with good synthetic control. The choice of the appropriate cyclization reaction leads to syntheses of the natural products sedamine and monomorine. The related N , O -acetals are shown to undergo efficient ring-opening under Sakurai conditions.