A convergent synthesis of the [4.4]-spiroacetal-γ-lactones cephalosporolides E and F
摘要:
A short convergent synthesis of the fungal metabolites cephalosporolides E and F is reported. The key step makes use of a chelation-controlled Mukaiyama aldol reaction to access the key acyclic spiroacetal precursor with the required syn stereochemistry. (C) 2010 Elsevier Ltd. All rights reserved.
Total Syntheses of Colletopeptide A and Colletotrichamide A
作者:Jing Chen、Yangyang Jiang、Jialei Yan、Chao Xu、Tao Ye
DOI:10.3390/molecules28207194
日期:——
The first totalsyntheses of cyclic depsipeptides colletopeptide A and colletotrichamide A, have been accomplished. The key advanced intermediate, a cyclic tridepsipeptide derivative, was constructed using a sequence of transformations that features asymmetric Brown crotylation, cross metathesis, Yamaguchi esterification, ozonolysis, and macrolactamization. A late-stage incorporation of the mannose
环缩酚肽colletopeptide A和colletorichamide A的首次全合成已经完成。关键的高级中间体,一种环状三缩酚肽衍生物,是通过一系列转化构建的,这些转化具有不对称布朗巴豆酰化、交叉复分解、山口酯化、臭氧分解和大环内酰胺化的特点。甘露糖片段的后期掺入完成了 colletorichamide A 的合成,并且常见中间体的脱甲硅烷基化产生了 colletopeptide A,从而明确证实了上述天然产物的绝对立体化学。
Stereoselective synthesis of the bacterial DNA primase inhibitor Sch 642305 and its C-4 epimer
作者:Jorge García-Fortanet、Miguel Carda、J. Alberto Marco
DOI:10.1016/j.tet.2007.09.080
日期:2007.12
A convergent stereoselective synthesis of the bacterial DNA primase inhibitor Sch 642305 and its non-natural epimer at C-4 is described. A key aspect was the construction of a trans-2,3-disubstituted cyclohexanone system by means of a stereoselective Michael addition/alpha-alkylation sequence. The macrolactone ring of either stereoisorner was created using the Mitsunobu and Yamaguchi procedures, respectively. (c) 2007 Elsevier Ltd. All rights reserved.