Synthesis and its application to the alkaloids synthesis of new 3-piperidinol type of chiral building blocks

This article describes a design and synthesis of new 3-piperidinol type of chiral building blocks and its application to the biologically active alkal oids synthesis. Both enantiomers of these chiral building blocks were prepa red by using a biocatalysis in enantiomerically pure state. As an applicati on of the above chiral building blocks to alkaloid synthesis, we demonstrat ed the diastereodivergent synthesis of the 8-piperidinol alkaloids cassine, spectaline, prosafrinine, iso-6-cassine, prosophylline, prosopinine, and a lso established the flexible route to the 5,8-disubstituted indolizidine or 1,4-disubstituted quinolizidine type of Dendrobates alkaloids. As another application to the synthesis of biologically active alkaloids, we accomplis hed the first enantioselective total synthesis of the marine alkaloids clav epictines A, B, and pictamine by using the highly stereoselective Michael t ype of quinolizidine ring closure reaction as the crucial step, respectivel y.