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Nicolaou小组报道了埃博霉素A的全合成,他们使用的合成策略是用烯烃复分解反应形成大环,虽然这一步选择性差,只有大约50%是所需要的顺式烯烃,但由于该反应操作简单,转化率高,反应可靠,选择性还有改进的余地,使用该反应进行关环成为重要的途径。全合成实际是由3个片段连接而成的。手性醛的合成通过手性茨内磺酰胺控制所需手性中心,丙酰基的α碳上不对称烷基化后水解还原得到醇,经钌催化氧化得到醛。手性酮酸片段由容易得到的
The complete synthesis of epothilone A has been reported by the Nicolaou group who used a synthetic strategy to form a macrocycle with an olefin metathesis reaction. Although this step selectivity is poor, only about 50% of the desired cis-olefin is needed, but due to the reaction procedure Simple, high conversion, reliable reaction, selectivity and room for improvement, the use of the reaction ring closure has become an important way. Total synthesis is actually connected by three fragments. The synthesis of chiral aldehyde by chiral cetane sulfonamide control the desired chiral center, propionyl α-carbon asymmetric alkylation after hydrolysis to give alcohol, the ruthenium obtained by catalytic oxidation of aldehydes. Chiral keto acid fragments are readily available