Asymmetric tandem Michael-Aldol reactions between 3-cinnamoyloxazolidine-2- thiones and aldehydes

Article abstract of DOI:10.1002/chem.200501435

Reactions between chiral 3-cinnamoyl-4-methyl-5-phenyl-1,3-oxazolidine-2- thiones and aromatic aldehydes in the presence of BF₃·Et ₂O diastereoselectively produced tricyclic compounds incorporating a bridgehead carbon bound to four heteroatoms in high yields. Four stereocenters were induced during the reaction. The tricyclic products were transformed into propane-1,3-diols bearing three consecutive stereocenters by acid hydrolysis, S-methylation, and reductive removal of the chiral auxiliary.