Synthetic approaches toward ecteinascidins .1. Preparation of an (E)-2-arylidene-3-benzyl-1,5-imino-3-benzazocin-4-one having a protected phenol in the E-ring
Synthetic approaches toward ecteinascidins .1. Preparation of an (E)-2-arylidene-3-benzyl-1,5-imino-3-benzazocin-4-one having a protected phenol in the E-ring
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DOI：
10.1039/a603292c
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发表时间：
1997-01-07
期刊：
影响因子：
--
通讯作者：
Kubo, A
中科院分区：
文献类型：
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作者：
Saito, N;Tashiro, K;Kubo, A
描述了从加勒比被囊动物 Ecteinascidia turbinata 中分离出的海鞘素的合成策略以及关键三环内酰胺中间体 32 的有效合成，关键步骤是将烯丙醇 15 分子内环化为 (E)-1,5-亚氨基-3-苯并佐辛 16，环化 15 (R = Me, Bn) 得到所需产物16的产率良好，然而，在酸性条件下处理15（R = MOM）以高产率得到化合物18，其结构通过X射线晶体学确定，最后16转化为(E)-N-甲基三环内酰胺32，可作为海鞘素的合成前体。
A synthetic strategy for the preparation of ecteinascidins isolated from the Caribbean tunicate Ecteinascidia turbinata and an efficient synthesis of a key tricyclic lactam intermediate 32 are described, The key step is the intramolecular cyclization of the allylic alcohol 15 to the (E)-1,5-imino-3-benzazocine 16, Cyclization of 15 (R = Me, Bn) afforded the desired product 16 in good yield, However, treatment of 15 (R = MOM) under acidic conditions gave compound 18 in high yield, the structure of which was determined by X-ray crystallography, Finally, 16 was converted into (E)-N-methyltricyclic lactam 32 that can serve as a synthetic precursor of ecteinascidins.