The regioisomers (2a,b) of the piperidine ring of febrifugine (1a) and isofebrifugine (1b) were synthesized from 4-allyl-3-piperidone (5). Reduction of 5 afforded a mixture of the trans and cis alcohols (6a,b) without diastereoselectivity
this result differentiated it from the reduction of 2-allyl-3-piperidone (14). The antimalarial di-activity of 2a,b and related compounds was tested.