Stereoselective Total Synthesis of (+)-Brevipolide H from d-Galactal
作者:Jun Liu、Ziyang Zhao、Qingwei Lv、Jialin Geng、Yang Liu、Chao Hu、Yuguo Du
DOI:10.1055/a-1700-3520
日期:2023.1
An efficient and concise synthesis of cytotoxic 5,6-dihydro-α-pyrone (+)-brevipolide H has been accomplished in 12 long linear steps in 8.65% overall yield from readily available chiral synthons, d-galactal and ethyl l-lactate. The features of this synthesis are highly diastereoselective Simmons–Smith cyclopropanation and carbohydrate-based chiron approach to rapid access to key 5,6-dihydro-α-pyrone
The enantioselective synthesis of natural brevipolide H is reported for the first time. By way of Sharpless epoxidation of penta-1,4-dien-3-ol, both enantiomerically pure epoxides were converted to the corresponding olefins for cross metathesis. Subsequent transformations, including epoxide ring opening, esterifications, cyclopropanation, oxidation and ring-closing metathesis, provided the target molecule
Absolute Configuration and Conformational Analysis of Brevipolides, Bioactive 5,6-Dihydro-α-pyrones from <i>Hyptis brevipes</i>
作者:G. Alejandra Suárez-Ortiz、Carlos M. Cerda-García-Rojas、Adriana Hernández-Rojas、Rogelio Pereda-Miranda
DOI:10.1021/np300740h
日期:2013.1.25
The (6′S)-configuration of brevipolides A–J (1–10), isolated from Hyptis brevipes, was established by X-ray diffraction analysis of 9 in conjunction with Mosher’s ester analysis of the tetrahydro derivative 11 obtained from both geometric isomers 8 and 9 as well as by chemical correlations. The structure of the new brevipolide J (10) was characterized through NMR and MS data as having the same 6-heptyl-5
所述(6'小号brevipolides的)构型A〜J(1 - 10),分离自毛老虎短柄,通过X射线衍射分析确定9结合四氢衍生物的Mosher氏酯分析11从两个几何异构体得到8和9以及化学相关性。通过NMR和MS数据表征新的brevipolide J(10)的结构为具有相同的6-庚基-5,6-dihydro-2 H -pyran-2-one骨架,该骨架具有所有brevipolides的环丙烷部分,但被取代异阿魏酰基而不是p-甲氧基肉桂酰基部分发现在8和9。通过比较实验和DFT计算的邻位1 H– 1 H NMR偶联常数,采用规程对化合物9进行了这些细胞毒性6-庚基5,6-二氢-α-吡喃酮的构象分析。分子建模被用于关联最小能量构象异构体和观察到的brevipolides异构体系列的电子圆二色性跃迁。化合物7 – 10对多种肿瘤细胞系表现出中等活性(ED 50 0.3–8.0μg/ mL)。