Using the capto-dative character of piperidine building block 1, the diastereomeric alpha -cyanoenamines 2a and 2b accompanied by dimer 5 were prepared through a SET pathway in a one-step procedure. Adjustment of the reaction conditions afforded either 2a or 2b as the major constituent. gamma -Alkylation of 2b with benzyl bromide proceeded smoothly.
Chiral Nonracemic Synthesis and Reactivity of Two New Endocyclic Enamines in the Phenyloxazolopiperidine Series