69 ビネオマイシン-フリダマイシン系抗生物質の全合成(ポスター発表の部)

概要

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Vineomycin-Fridamycins, a class of quinone antibiotics isolated from Streptomyces matensis and Streptomyces parvulus, have synthetically attractive structure composed of three dissimilar components, i.e., an anthraquinone chromophore, a C-glycosidated sugar, and the characteristic side chain. In the present study, we developed efficient processes for the connection of these three components, and achieved the total synthesis of vineomycinone B_2. 1) O→C-glycoside rearrangement: The reaction between glycosyl fluoride 2 and anthracene 4 was effected by Cp_2HfCl_2-AgClO_4 to give β-glycoside 5 as a sole product in high yield. 2) Introduction of the side chain: The ortho-metallation of glycoside 5 proceeded cleanly by using ^tBuOK-^nBuLi as a base, and subsequent trapping by Me_3SnCl afforded stannane 19. Its transmetallation was effected by using MeLi in toluene. Subsequent addition of aldehyde 14, available in optically pure form by biochemical method, gave the coupling product in high yield. 3) Total synthesis: Total synthesis of vineomycinone B_2 was achieved via deoxygenation at C-11 by Na_2S_2O_4 followed by oxidation of C14-C15 double bond of 20.
天然有機化合物討論会の論文
1990-09-25