Part I. asymmetric organocatalysis: 1. direct enantioselective organocatalytic hydroxymethylation of aldehydes catalyzed by α,α-diphenylprolinol trimethylsilyl ether: application in the formal synthesis of (-)-Rasfonin; 2. synthesis of a novel bicyclic secondary amine organocatalyst: application to the direct enantioselective organocatalytic hydroxymethylation of aldehydes Part II. asymmetric synthesis of bicyclic analogues of the anti-osteoporotic drug Risedronate