Enantioselective Total Synthesis of (−)‐Spiroxins A, C, and D
作者:Xin Shu、Chong‐Chong Chen、Tao Yu、Jiayi Yang、Xiangdong Hu
DOI:10.1002/anie.202105921
日期:2021.8.16
targets for the synthetic community. Based on a scalable enantioselective epoxidation of 5-substituted naphthoquinone, an oxidation/spiroketalization cascade, ortho-selective chlorination of the phenol unit, and oxime-ester-directed acetoxylation, an enantioselectivetotalsynthesis of (−)-spiroxins A and C and the first totalsynthesis of (−)-spiroxin D have been achieved.
螺环素 A、C 和 D 是已在海洋真菌菌株 LL-37H248 中鉴定的代谢物。它们独特的多环结构和有趣的生物活性使它们成为合成社区的有吸引力的目标。基于 5-取代萘醌的可扩展对映选择性环氧化、氧化/螺酮缩酮级联、苯酚单元的邻位选择性氯化和肟酯导向的乙酰氧基化、(-)-螺环素 A 和 C 的对映选择性全合成以及已经实现了 (-)-spiroxin D 的首次全合成。
Asymmetric weitz - scheffer epoxidation promoted by bovine serum albumin
作者:Stefano Colona、Nicoletta Gaggero、Amedea Manfredil、Massimo Spadoni、Luigi Casella、Giacomo Carrea、Piero Pasta
DOI:10.1016/s0040-4020(01)86023-3
日期:1988.1
The epoxidation of 2-substituted naphthoquinones with t-BuOOH in an aqueous buffer solution containing a small amount (up to 5 % molar equiv) of bovine serum albumin (BSA) gives the corresponding epoxides with enantiomeric excess (e.e.) up to 100 %. The enantioselectivity is very sensitive to the addition of water miscible or immiscible cosolvents and to the length of the alkyl chain in position 2