作者:Kazuo Okumura、Taishi Suzuki、Yutaka Nakamura、Chung-gi Shin
DOI:10.1246/bcsj.72.2483
日期:1999.11
The first total synthesis of a macrocyclic antibiotic, micrococcin P1 (1), was achieved. This antibiotic has a unique structure and is constructed of four components called Fragments A, B, C, and D. In particular, the structures of the central pyridine skeleton (Fragment A) and the exocyclic side-chain (Fragment D) of 1 are slightly different from those of a similar antibiotic, micrococcin P (2). By various chemical modifications of the synthetic method for 2, the synthesis of the central 2,3,6-tris(substituted thiazolyl)pyridine segment [Fragment A—C] 15 from ethyl 2-[6-dimethoxymethyl-2-(1-ethoxyvinyl)-3-pyridyl]thiazole-4-carboxylate (9), followed by coupling of 15 with the Fragments B and D moieties, synthesized independently, gave the protected Fragment A-B-C-D segment. Final intramolecular cyclization by using (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate as a condensing agent under high-dilution conditions and then deprotection of all the protecting groups with trifluoroacetic acid were effected successfully to give the expected synthetic 1.
首次实现了大环抗生素微球菌素 P1 (1) 的全合成。这种抗生素具有独特的结构,由称为片段 A、B、C 和 D 的四种成分构成。特别是 1 的中心吡啶骨架(片段 A)和环外侧链(片段 D)的结构是与类似抗生素微球菌素 P 略有不同 (2)。通过对2的合成方法进行各种化学修饰,由乙基2-[6-二甲氧基甲基-2-(1-)合成中心2,3,6-三(取代噻唑基)吡啶片段[片段AC]15乙氧基乙烯基)-3-吡啶基]噻唑-4-羧酸酯(9),然后将独立合成的15与片段B和D部分偶联,得到受保护的片段A-B-C-D片段。在高稀释条件下使用(苯并三唑-1-基氧基)三(二甲氨基)鏻作为缩合剂,最终进行分子内环化,然后用三氟乙酸脱去所有保护基,得到预期的合成物1。