Synthesis of spirolactones by 1, 3??dipolar cycloadditions to methyl (S)??3??[(E)??cyanomethylidene]??2??oxotetrahydrofuran??5??carboxylate

…, J Svete, L Golič, A Meden, B Stanovnik

文献索引：Pirc, Samo; Recnik, Simon; Skof, Marko; Svete, Jurij; Golic, Ljubo; Meden, Anton; Stanovnik, Branko Journal of Heterocyclic Chemistry, 2002 , vol. 39, # 2 p. 411 - 416

全文：HTML全文

被引用次数: 14

摘要

Treatment of methyl (S)-5-[(E)-(dimethylamino) methylidene]-2-oxotetrahydrofuran-5- carboxylate (2) with potassium cyanide in acetic acid gave (S)-5-[(E)-cyanomethylidene]-2- oxotetrahydrofuran-5-carboxylate (3), which was used as chiral dipolarophile in 1, 3-dipolar cycloadditions. Reactions of 3 with diazomethane (4) and nitrile oxides 5a–c afforded spirolactones 6–8 in 24–34% diastereomeric excess, while with diazomethane (4) in the ...