Highly stereocontrolled total synthesis of the polyether antibiotic salinomycin. III. Total synthesis of salinomycin via coupling of C1-C9, C10-C17, and C-18-C30 segments.
作者:Kiyoshi HORITA、Yuji OIKAWA、Satoshi NAGATO、Osamu YONEMITSU
DOI:10.1248/cpb.37.1717
日期:——
The polyether antibiotic salinomycin was synthesized via coupling between the C10-C17 aldehyde, (2R, 4S, 5S, 6S, 7R)-6-ethyl-5, 7-isopropylidenedioxy-2, 4-dimethylnonanal, and C18-C30 acetylenes, for example, (3R, 4R, 7S)-4, 7-bis(tert-butyldimethylsilyloxy)-7-[(2R, 5R, 6S)-5-ethyl-5-(4-methoxybenzyloxy)-6-methyltetra-hydropyran-2-yl]-3-(4-methoxybenzyloxy)oct-1-yne, followed by the aldol condensation with the C1-C9 segment, (R)-2-[(2R, 5S, 6R)-6-[(R)-1-formylethyl]-5-methyltetrahydropyran-2-yl]butanoic acid. In this total synthesis, protection of hydroxy groups with the 4-methoxybenzyl group played an important role.
聚醚抗生素沙林霉素是通过 C10-C17 醛、(2R, 4S, 5S, 6S, 7R)-6-ethyl-5, 7-isopropylidenedioxy-2, 4-dimethylnonanal 与 C18-C30 乙炔基(例如,(3R, 4R, 7S)-4, 7-双(叔丁基二甲基硅氧基)-7-[(2R. 5R, 6S)-5-ethyl-5-(4- 甲氧基苄氧基)-6-甲基四氢吡喃-2-基]-3-(4-甲氧基苄氧基)-6-甲基四氢吡喃-2-基]之间的偶联合成的、5R,6S)-5-乙基-5-(4-甲氧基苄氧基)-6-甲基四氢吡喃-2-基]-3-(4-甲氧基苄氧基)辛-1-炔,然后与 C1-C9 段的(R)-2-[(2R,5S,6R)-6-[(R)-1-甲酰基乙基]-5-甲基四氢吡喃-2-基]丁酸进行醛醇缩合。在整个合成过程中,用 4-甲氧基苄基保护羟基起了重要作用。