A Straightforward and Efficiently Scaleable Synthesis of Novel Racemic 4-Substituted-2,8-diazaspiro[4.5]decan-1-one Derivatives

ABSTRACT Novel and straightforward syntheses (3-5 steps, high yields) of racemic diazaspiropiperidine derivatives based on the Michael addition of pipecolate-derived enolates to a range of nitroalkenes have been developed. The reaction has been shown to have a general scope and can be conducted on a preparatively useful scale. Isolation and identification of diazaspiropiperidine enantiomers was efficiently achieved using normal phase chiral HPLC.