キラルトリフラート法-光学活性天然物合成の新手法

抄録

The chiral building block approach to enantiomerically pure compound synthesis is known as “chiral pool method” and extensively employed for the synthesis of biologically interesting natural products. In spite of its great synthetic utility, frequently it becomes a serious problem to elaborate the side chain on the carbon center bearing a β-oxygen functionality. However, because of the electron-withdrawing nature of β-oxygen it is generally accepted that alkylation through nucleophilic displacement reaction is not so easy. In order to overcome this difficulty we have designed to use the trifluoromethanesulfonates (triflates) as extremely reactive substrates for the required carbon-carbon bond-forming reaction. That is, the alkylation of chiral triflate derivatives with Grignard or organolithium reagents provides a new rapid means for natural product synthesis and the method is termed as “chiral triflate technology”. In this article, total syntheses of (+) -exo-brevicomin, L-factor, the cyclohexyl fragment of FK-506, (+) -diolmycin A2, (+) -panaxacol, renin inhibitor, and AI-77-B starting from L- or D- tartaric acid or D-ribose as a chiral source are described.