The stereoselective synthesis of piperidine heterocycles with varying substitution patterns is of general interest in medicinal chemistry. Consequently, we have developed methodology for the enantioselective formation of piperidine alkaloids using glycosylamines as chiral auxiliaries. Starting from per-O-pivaloylated d-galactosylamine we were able to synthesise 2-substituted 5,6-dehydropiperidinone derivatives in excellent yield and high stereoselectivity.

Based on this highly functionalised heterocyclic scaffold we performed various transformations to obtain a number of natural products and a multitude of further piperidine derivatives.

Using the same concept we recently discovered a new entry to the core structure of opiod analgesics and herein report a short stereoselective synthesis of 6,7-benzomorphans and their regioisomers the 7,8-benzomorphans.