An Efficient Synthesis of Oxazolidines by Tandem Ring-Opening / Closing Reaction of Ts-Aziridine Using Formic Acid

Abstract

Synthesis of oxazolidines has been reported from aziridines by the reaction with formic acid and formaldehyde in neat conditions. We have also observed a regio-selective nucleophilic ring opening of aziridines by HCOOH under same conditions in absence of formaldehyde where the HCOO− ion acts as a nucleophile. In this present method formic acid is not acting as reducing agent as classical organic reactions. The formic acid initially activates the aziridines whereas the formate group generated from formic acid acts as a nucleophile itself instead of the source of hydride ion affording the nucleophilic ring opening products. The synthesized formate ester was successfully hydrolyzed to the corresponding hydroxyl compound which is the key building block for the synthesis of heterocycles. Operational simplicity, mild and neat reaction conditions, broad substrates scope, good yields and uses of less expensive reagents are the notable advantages of the present procedures. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim