Studies On The Gold-catalyzed Cyclization To Pyrrolines And The Synthesis Of The Calyciphylline A-type Daphniphyllum

The thesis aims at the synthetic studies of gold(I)-catalyzed tandem reaction of γ-amino-substituted propargyl esters to pyrrolines and the synthesis of the Calyciphylline A-type Daphniphyllum alkaloids.It consists of the following three parts:Chapter 1.The Synthesis of Spirocyclics in the Total Synthesis of Natural Products(review)The applications of the synthetic methods to constuct spiro compounds in total synthesis of natural products are reviewed.Chapter 2.Gold(I)-Catalyzed Tandem Reaction of γ-Amino-Substituted Propargyl Esters to Pyrrolines and its ApplicationAn effective synthesis of structurally diverse pyrroline derivatives has been accomplished by a gold(I)-catalyzed tandem 1,3-acyloxy rearrangement/intramolecular aza-cylization reaction of γ-amino-substituted propargyl esters in good to excellent chemical yields(52%-98%).The reaction proceeds under extremely mild conditions,which demonstrated its potential in a concise formal synthesis of(±)-Aphanorphine.Chapter 3.Synthetic Studies towards the Structure of Calyciphylline A-type Daphniphyllum AlkaloidsThe synthetic studies towards the Calyciphylline A-type Daphniphyllum alkaloids have been performed and identified the 6-5-7-5-5-fused pentacyclic system as the core structure to be constructed,featuring Michale/Michael cascade/Pauson-Khand reaction.This work is on going.