Enantioselective Ring Expansion of Prolinols: An Efficient and Short Synthesis of 2-Phenylpiperidin-3-ol Derivatives and 3-Hydroxypipecolic Acids

Abstract

A very short route to 2-phenylpiperidin-3-ol derivatives and 3-hydroxypipecolic acids is described. The approach uses two key steps: a one-pot reduction/Grignard addition sequence applied to alkyl proline esters and a ring expansion applied to the corresponding prolinols.