Synthesis of protected chiral vicinal diaminoalcohols by diastereoselective intramolecular benzylic substitution from bistrichloroacetimidates.

Christophe Rondot, Pascal Retailleau, Jieping Zhu

Index: Org. Lett. 9 , 247, (2007)

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Abstract

An efficient synthesis of chiral dihydrooxazines (2) from 1-aryl-2-amino-propane-1,3-diols (1) via the corresponding bistrichloroacetimidate intermediates has been developed. In this transformation, one trichloroacetimidate acts as a leaving group and the other acts as a nucleophile. The cyclization proceeds through an SN1 mechanism to provide trans-dihydrooxazines with complete diastereoselectivity irrespective of the absolute configuration of the benzylic alcohol. The transformation of 2 into other selectively protected aminodiols is also documented. [reaction: see text].