Regiospecific and Enantiospecific Ring Opening of Methyl (+)-(1'R, 2R)- and (-)-(1'R, 2S)-1-(2-phenylethanol) Aziridine-2-carboxylates

Dino Gnecco,Raúl G Enríquez,Laura F Orea,W F Reynolds,Alberto Galindo,R A Toscano

doi:10.3390/50800998

Abstract

The acid-catalyzed ring-opening of methyl (+)-(1'R, 2R) and (-)-(1'R, 2S)-1-(2-phenylethanol) aziridine-2-carboxylates (1) and (2) lead quantitatively to the corresponding 2(S)-(-)-chloro-3-[2'-hydroxy-1'(R)-phenyl-ethylamino] propionic acid methyl ester (3) and 2(R)-(-)-chloro-3-[2'-hydroxy-1'(R)-phenyl-ethylamino] propionic acid methyl ester (4) hydrochlorides.

Highlights

The ring-opening reactions of aziridines by hydrogen halides, water and other nucleophiles are among the oldest known reactions of aziridines and have been studied extensively [1,2,3]
The strain associated with the three member ring of aziridine accounts for its reactivity towards ring opening, while additional regio- and stereochemical control on the ring opening reaction can be gained by the presence of specific substituents
Aside from the products (3HCl) or (4HCl), no spots correpsonding to the starting materials were detected

Summary

Introduction

The ring-opening reactions of aziridines by hydrogen halides, water and other nucleophiles are among the oldest known reactions of aziridines and have been studied extensively [1,2,3]. The ringopening of aziridines provides a route for the synthesis of haloamines. The strain associated with the three member ring of aziridine accounts for its reactivity towards ring opening, while additional regio- and stereochemical control on the ring opening reaction can be gained by the presence of specific substituents. We are concerned with the stereochemical control of such ringopening reactions, which becomes very important in regard to making these reactions synthetically useful. The mechanism and regioselectivity of the acid catalyzed ring-opening of the nonactivated aziridine2-carboxylates may exhibit important differences, depending on the conditions used, as it was demonstrated by E. Kyburz et al [4], Scheme 1

H N CO2Me H

Results and Discussion

Conclusions