Studies Toward Synthesis Of Cephalotaxine And Construction Of Stenine Skeleton

This thesis is aimming at the synthetic study of Cephalotaxine(CET), construction of Stenine skeleton and consists of the following three parts:In Charpter 1 the isolation, chemical structure identification, biological activities of Cephalotaxine was described and reviewed total synthesis of Cephalotaxine via spiro compound. A facile protic acid-mediated Friedel-Crafts cyclization was described and finished the synthesis of Cephalotaxine in this way. We also explained the process of isomerization of CET skeleton compound.In Charpter 2 total synthesis of Stenine was reviewed at first, and described the Mn(OAc)₃·2H₂O-mediated free radical cyclization and Clemmensen reductive rearrangement as key reaction. The tricyclic system 5-6-7 of Stenine skeleton was finished, At the same time, also finished the skeleton of Aspidosperma via reduction free radocal cyclization and Clemmensen reductive rearrangement. In Charpter 3 the purpose of Zn/HOAc in organic synthesis was reviewed at first, and described the a new reduction breaking carbon-nitrogen bond reaction. the mechanism of this reaction is studied with methyl and atom deuterium.