An enantioselective synthesis of (-)-prosophylline has been accomplished in 15 steps from protected d-glyceraldehyde, with an overall yield of 9.2%, by using two enantioselective allyltitanations and a cross-metathesis reaction as the key-steps.
An enantioselectivesynthesis of the piperidine alkaloids (+)-sedamine and (-)-prosophylline is reported. The synthesis of (+)-sedamine has been achieved in 12 steps with an overall yield of 20% from benzaldehyde, and (-)-prosophylline was obtained in 15 steps with an overall yield of 9.2%, starting from D-glyceraldehyde acetonide 14. The key steps are enantioselective allyltitanation reactions and