A versatile new method for the synthesis of various pyrrolidin-1-oxyl fatty acids

Abstract

Mono-and di-carboxylic acid derivatives of various structural isomers the pyrrolidin-1-oxyl ring containing a stable free radical (spin label)can be obtained by Michael addition of a nitroalkane to an α,β-unsaturated ketone ot give a γ-nitroketone, followed by ring closure to a pyrrolin-1-yl oxide which reacts with Grignard reagents to give a pyrrolidin-1-oxyl compound, which undergoes phase-transfer oxidation of its terminal unsaturated bond.