| সংক্ষিপ্ত: | <p>This thesis is concerned with the application of the conjugate addition of functionalised lithium amides in the asymmetric syntheses of (−)-morphine and all members of the homalium alkaloids. Chapter 1 introduces the conjugate addition reaction as an important bond forming reaction, and explores its utility in the asymmetric synthesis of a variety of natural products. The conjugate addition of secondary lithium amides derived from α-methylbenzylamine is discussed, along with its application to the asymmetric synthesis of alkaloids.</p><p>Chapter 2 describes two distinct attempts towards the asymmetric synthesis of (−)-morphine, both reliant upon the lithium amide conjugate addition and an intramolecular Diels-Alder reaction to set the five required stereogenic centres. The use of the novel and highly functionalised reagent lithium (R)-N-[2′-(7-methoxybenzofuran-3-yl)ethyl]-N-(α-methylbenzyl)amide and its derivatives is reported.</p><p>Chapter 3 focuses on the use of the novel reagent lithium (R)-N-(3-chloroprop-1-yl)-N-(α-methylbenzyl)amide and its derivatives in the asymmetric synthesis of two of the homalium alkaloids, (−)-(S,S)-homaline and (−)-(R,R)-hopromine, culminating in the most efficient syntheses of these alkaloids to date. Further, a sample of the (4′R,4′′S)-diastereoisomer of hopromine was synthesised, serving to confirm the proposed absolute configuration within natural (−)-(R,R)-hopromine.</p><p>Chapter 4 extends the methodology developed in chapter 3 to the asymmetric synthesis of all possible diastereoisomers of the remaining homalium alkaloids, (−)-hopromalinol and (−)-hoprominol. These syntheses were used to propose the absolute configurations within these alkaloids, and therefore represented the first asymmetric syntheses of natural (−)-(4′S,4″R,2‴R)-hopromalinol and (−)-(R,R,R)-hoprominol.</p><p>Chapter 5 contains full experimental procedures and characterisation data for all compounds synthesised in Chapters 2, 3 and 4.</p>
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