Studies on the synthesis of 8-alkyl-8-aryl-2-azabicyclo[3.3.1]nonan-7-ones. A short synthetic route to functionalized 8-alkyl derivatives

Abstract

Two approaches to 8-alkyl-8-aryl-2-azabicyclo[3.3.1]nonan-7-ones are explored. They are based on the cyclization of an α-alkyl α-aryl ketone upon an iminium salt generated from 2-cyanopiperidine 13 and on the arylation of 8-alkyl-2-azabicyclo[3.3.1]nonan-7-one 20. An efficient, short synthetic route to 8-alkyl-2-azabicyclo[3.3.1]nonan-7-ones, using phosphonate 16 as a 5-functionalized 2-oxopentyl synthon, is reported.