Synthesis of trans-2,6-dialkylpiperidines by intramolecular amidomercuriation and by 1,3-cycloaddition of alkenes to 2-methyl-2,3,4,5-tetrahydropyridine oxide

Abstract

Intramolecular amidomercuriation of methyl N-hept-6-en-2-ylcarbamate and reaction of the resulting organomercurial with sodium borohydride in the presence of acrylonitrile or dec-1-en-3-one has been used to prepare trans-2,6-dialkylpiperidines. A more stereoselective route lies in the cycloaddition of alkenes to 2-alkyl-2,3,4,5-tetrahydropyridine oxides followed by reductive cleavage of the resulting perhydroisoxazolopyridine. Both procedures are illustrated by synthesis of the fire ant-venom alkaloid, solenopsin A.