Microwave-assisted regioselective ring opening of non-activated aziridines by lithium aluminium hydride

Abstract

A new synthetic protocol for the LiAlH₄-promoted reduction of non-activated aziridines under microwave conditions was developed. Thus, ring opening of 2-(acetoxymethyl)aziridines provided the corresponding β-amino alcohols, which were then used as eligible substrates in the synthesis of 5-methylmorpholin-2-ones via condensation with glyoxal in THF. The same procedure was applied for the preparation of novel 5(R)- and 5(S)-methylmorpholin-2-ones starting from the corresponding enantiopure 2-(hydroxymethyl)aziridines. Additionally, 2-(methoxymethyl)- and 2-(phenoxymethyl)aziridines were treated with LiAlH₄ under microwave irradiation, giving rise to either isopropylamines or 1-methoxypropan-2-amines depending on the reaction conditions.