Approaches to Unsaturated Analogues of Nucleosides Comprising Four- and Six-Membered Rings
作者:Hui-Ping Guan、Mohamad B. Ksebati、Earl R. Kern、Jiri Zemlicka
DOI:10.1021/jo000276p
日期:2000.8.1
35 as minor components. Vicinal dibromide 30b gave the Zaitsev cyclohexene 45 as the only product. Epoxidation of 29a and 29b afforded oxiranes 36a and 36b which were used in alkylation of adenine to furnish hydroxy derivatives 37a, 37b, 38a, and 38b. Beta-elimination via mesylates 39a and 40a using tBuOK/DMF gave Z- and E-methylenecyclobutanes 34 and 35. With an excess of base the E-bis-methylenecyclobutane