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 alkaloids synthesis. Both enantiomers of these chiral building blocks were prepared by using a biocatalysis in enantiomerically pure state. As an application of the above chiral building blocks to alkaloid synthesis, we demonstrated the diastereodivergent synthesis of the 8-piperidinol alkaloids cassine, spectaline, prosafrinine, iso-6-cassine, prosophylline, prosopinine, and also 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 accomplished the first enantioselective total synthesis of the marine alkaloids clavepictines A, B, and pictamine by using the highly stereoselective Michael type of quinolizidine ring closure reaction as the crucial step, respectively.