Studies On The Asymmetric Syntheses Of (－)-Bitungolide F And (－)-Pandangolide 1a

This dissertation aims at the studies on the asymmetric syntheses ofdihydropyrone natural product (-)-Bitungolide F and macrolide natural product(-)-pandangolide 1a. It consisted of the following three parts:Chapter 1. Methods for oxidation of alcohols to aldehydes and ketones (Review).The introduction of oxidation of alcohols to aldehydes and ketones wasdescribed, which consisted of the following eight aspects: (1) Chromium-BasedReagents; (2) Activated Dimethy Sulfoxide; (3) Hyervalent Iodine Compounds; (4)Ruthenium-Based Oxidations; (5) TEPO; (6) Oxidation by Hydride Transfer from aMetallic Alkoxide; (7) F(?)tizon reagent; (8) Selective Oxidations.Chapter 2. Studies on the asymmetric synthesis of (-)-Bitungolide F.The work of our group in synthesis of dihydropyrone natural products wasintroduced briefly.An efficient total synthesis of(-)-bitungolide F from natural malic acid in 17steps and 20.1 % yield was described. Key steps involve hydroxy-directed reduction, aMyers asymmetric alkylation, an Evans aldol reaction, a Claisen-like cyclization anda Julia-Kocienski olefination, which further confirms the absolute stereochemistry ofbitungolide F and lays down a foundation for further diversity of total synthesis ofbitungolides A-E.Chapter 3. Studies on the asymmetric synthesis of (-)-Pandangolide 1a.The work of our group in synthesis of macrolide natural products was introducedbriefly.The efficient asymetric synthesis of 12-membered precursor of pandangolide 1a has been achieved via a Keck reaction, a RCM reaction staring from natural malicacid, (S)-proplene oxid and 6-Br-1-hexene.