Total synthesis of the piperidinol alkaloid (-)-(2R,3R,6S)-cassine

Article abstract of DOI:10.1016/S0957-4166(96)00537-X

A highly efficient, flexible and diastereoselective route to all-cis-2,6-disubstituted 3-piperidinols has been accomplished. The key component of the synthesis is a chiral β-hydroxyester, which was obtained by lipase catalyzed kinetic resolution. Based on this starting material, diastereoselective alkylation of its dianion, Curtius rearrangement to a 2-oxazolidinone, Grignard reaction to introduce the side-chain and conversion of the aliphatic 2-oxazolidinone into a 3-piperidinol by imine cyclization lead to the exemplary total synthesis of naturally occurring (-)-(2R,3R,6S)-cassine.