An Efficient Method for the Synthesis of Nitropiperidones

A three step efficient strategy for the synthesis of substituted 5-nitropiperidones in high de, employing Michael addition of N-p-tolylsulfinyl β-nitroamines to α,β-unsaturated esters, hydrolysis of the sulfinyl group, and cyclization of the resulting free amines, has been developed. A very simple experimental procedure involving mild conditions and only one chromatographic purification are the main features of the process.