Efficient Approach to Fluvirucins B2-B5, Sch 38518, and Sch 39185. First Synthesis of their Aglycon, via CM and RCM Reactions
Efficient Approach to Fluvirucins B2-B5, Sch 38518, and Sch 39185. First Synthesis of their Aglycon, via CM and RCM Reactions
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DOI：
10.1021/ol901030f
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发表时间：
2009-08-06
期刊：
影响因子：
5.2
通讯作者：
Vilarrasa, Jaume
中科院分区：
文献类型：
--
作者：
Llacer, Enric;Urpi, Felix;Vilarrasa, Jaume
首次报道了氟病毒菌素B2-5（氟病毒菌素B-2-B-5、Sch 38518和Sch 39185的共同苷元）的合成路线。闭环复分解（RCM）产生C6-C7双键，其通过催化氢化（在甲苯中）以9：1非对映选择性得到所需差向异构体。叠氮化物8a和羧酸5来自乙基支化片段C9-C13（C9处的CHO）和C1-C5，通过前者的不对称烯丙基化和后者的交叉复分解（CM），随后酮亚甲基化（用20摩尔%的DMF作为牺牲添加剂）。
A route to fluvirucinins B2-5 (the common aglycon of fluvirucins B-2-B-5, Sch 38518, and Sch 39185) is reported for the first time. A ring-closing metathesis (RCM) generated the C6-C7 double bond, which by catalytic hydrogenation (in toluene) gave the desired epimer with a 9:1 diastereoselection. Azide 8a and carboxylic acid 5 came from ethyl-branched fragments C9-C13 (CHO at C9) and C1-C5 via an asymmetric allylation of the former and a cross metathesis (CM) followed by a ketone methylenation (with 20 mol % of DMF as a sacrificial additive) of the latter.