Intra- and Intermolecular Oxa-Pictet-Spengler Cyclization Strategy for the Enantioselective Synthesis of Deoxy Analogues of (+)-Nanomycin A Methyl Ester, (+)-Eleutherin, (+)-Allo-Eleutherin, and (+)-Thysanone
作者:Rajiv T. Sawant、Satish G. Jadhav、Suresh B. Waghmode
DOI:10.1002/ejoc.201000476
日期:——
Enantioselectivesynthesis of deoxy analogues of pyranonaphthoquinone antibiotics (+)-nanomycin A methylester, (+)-eleutherin, (+)-allo-eleutherin, and (+)-thysanone was achieved in good overall yield with high enantio- and diastereoselectivity from the common intermediate (R)-3-(2,5-dimethoxyphenyl)propane-1,2-diol. The intramolecular oxa-Pictet–Spengler cyclization of 6-aryl-1,3-dioxolone was developed
吡喃萘醌类抗生素 (+)-纳米霉素 A 甲酯、(+)-eleutherin、(+)-allo-eleutherin 和 (+)-thysanone 的脱氧类似物的对映选择性合成以良好的总收率实现,具有高对映选择性和非对映选择性常见的中间体(R)-3-(2,5-二甲氧基苯基)丙烷-1,2-二醇。首次开发了 6-芳基-1,3-二氧戊环的分子内氧杂-Pictet-Spengler 环化,并将其用于 (+)-脱氧纳米霉素 A 甲酯的对映选择性合成,而分子间氧杂-Pictet-Spengler 环化策略应用于 (+)-eleutherin、(+)-allo-eleutherin 和 (+)-thysanone 脱氧类似物的对映选择性合成。
First asymmetric total synthesis of novel and cytotoxic 2′-R-hydroxylanneaquinol
作者:V. Suresh、K. Rajesh、J. Jon Paul Selvam、Y. Venkateswarlu
DOI:10.1016/j.tetlet.2008.09.076
日期:2008.12
A novel cytotoxic alkylated hydroquinone 2'-R-hydroxylanneaquinol (1), isolated from the organic extract of the plant Lannea welwitschii, has been synthesized for the first time using commercially available 4-methoxyphenol. The key step of this process involves the kinetic resolution of epoxide 6 using Jacobsen's reaction conditions. (C) 2008 Elsevier Ltd. All rights reserved.