An efficient and highly convergent totalsynthesis of the potentantitumor agent phorboxazole B has been achieved. The synthetic strategy of this synthesis features: 1) a highly efficient substrate-controlled hydrogenation to construct the functionalized cis-tetrahydropyrane unit; 2) iterative crotyl addition to synthesize the segment that contains alternating hydroxyl and methyl substituents; 3) Hg(OAc)2/I2-induced
已经实现了有效的和高度收敛的有效的抗肿瘤药phorboxazole B的全合成。该合成方法的合成策略为:1)高效的底物控制的氢化反应,以构建官能化的顺式-四氢吡喃单元;2)重复的巴豆基加成反应,以合成含有交替的羟基和甲基取代基的链段;3)Hg(OAc)2 / I 2诱导的环化以建立顺式-四氢吡喃部分;4)在Mukaiyama aldol反应中的1,3-不对称诱导以在C9和C3处提供立体异构中心;5)探索Still-Gennari烯化反应以完成佛波唑唑B的大环内酯环。
Formal synthesis of Cladospolide C & epi-Cladospolide C using R-(+)-γ-valerolactone as a chiral synthon
The formalsynthesis of Cladospolide-C and its analog is achieved by using enantiopure (R)-γ–valerolactone 10. The significant points of this synthesis are the stereoselective dihydroxylation of α, β-unsaturated ester 16 using Sharpless protocol, Wittig olefination of γ –valerolactol 6 with triphenylphosphonium iodide salt 7, one pot selective oxidation of 22 and subsequent C2-homologation with good