Year

1991

Degree Name

Doctor of Philosophy

Department

Department of Chemistry

Abstract

This thesis investigates the application of chiral sulfoxides and sulfoxmines to the asymetric synthesis of chiral alcohols, amines and isoquinoline alkaloids, the results are presented in five chapters.

In chapter 1 the addition of the anions of methyl phenyl and methyl p-tolysulfoxide to imines was shown to be highly diastcrcoselctive process under kinetically controlled conditions. This method was extended to the asymmetric synthesis of R(+) tetrahydropalmatine.

Chapter 2 is an extension of this method to methyl phenylsulfoximines. The relative stereochemistry of major adduct between lithiated t-butyldiphenylsilyl sulfoximine and benzylideneaniline was determined by x-ray crystalography.

In chapter 3 an attempt was made to extend this methodology to the synthesis of benzyl isoquinoline alkaloids. However, both the yields and diastereoselctivity were poor.

Chapter 4 deals with an attempt to solve the problems encountered with benzylmethylsulfoxide (in chapter 3). However the addition of the dianions of (Rs)-lO-methyl and (Rs)-10-Benzyl-sulphinylbornan-2-Exo-ol to imines gave low yields and poor diastereoselectivity. Attempts to silysate these sulfoxides gave a number of novel Pummerer rearrnagements products.

Chapter 5 deals with the successful application of benzyl methyl and benzylphenylsulfoximines to the synthesis of chiral amines, alcolhols and 1-benzyl isoquinoline derviatives. The stereochemistry at these adducts was determined by x-ray crystalography.

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