Jaspamide (Jasplakinolide), a marine cyclodepsipeptide, was synthesised from tripeptide fragment 4 and (2S,4E,6R,8S)-8-benzoyloxy-2,4,6-trimethylnon-4-enoic acid (3). The tripeptide fragment was prepared from β-tyrosine derivative 6, Boc-2-bromoabrine (8), and alanine. β-Tyrosine derivative 6 was prepared by asymmetric conjugate amination of methyl p-hydroxycinnamate. Bromabrine derivative 8 was prepared from tryptophan. Key steps in the synthesis of the polyketide fragment 3 include 1,2-metallate rearrangement of a metallated dihydropyran and a metallated enol carbamate derivative.
由三肽片段 4 和 (2S,4E,6R,8S)-8-苯甲酰氧基-2,4,6-三甲基壬-4-烯酸 (3) 合成了海洋环肽 Jaspamide (Jasplakinolide)。三肽片段是由δ-
酪氨酸衍
生物 6、Boc-2-
溴肾上腺素(8)和丙
氨酸制备而成。δ-
酪氨酸衍
生物 6 是通过
对羟基肉桂酸甲酯的不对称共轭胺化反应制备的。
溴苦参碱衍
生物 8 由色
氨酸制备。合成多酮片段 3 的关键步骤包括
金属化二氢
吡喃和
金属化烯醇
氨基甲酸酯衍
生物的 1,2-
金属化重排。