A highly stereoselective asymmetric synthesis of (-)-lobeline and (-)-sedamine

A highly stereoselective asymmetric synthesis of (-)-sedamine and (-)-lobeline is described from benzaldehyde in 16 and 17 steps with an overall yield of 20% and 14%, respectively. The key intermediate syn-3,4-epoxyalcohol was prepared in a highly diastereomeric fashion (>99% ee, dr) and served as a common intermediate for both alkaloids.