Lateral Lithiation-Initiated Annulations in the Synthesis of 1-Oxygenated Carbazole Alkaloids and a Cycloheptacarbazole
作者:Dipakranjan Mal、Amit Jana、Pallab Pahari
DOI:10.1055/s-0031-1290380
日期:2012.7
Anionic [4+2] annulation of lithiated furoindolones with dimethyl maleate followed by selective demethoxycarbonylation provides an efficient synthetic route to 3-methoxycarbonylcarbazoles. The route has led to the straightforward synthesis of two natural products, namely clausine E, mukonine, and their 4-prenyl analogues. A new route to cyclohepta[d,e,f]carbazole was also uncovered during the investigations
锂化呋喃吲哚酮与马来酸二甲酯的阴离子 [4+2] 环化,然后选择性脱甲氧基羰基化为 3-甲氧基羰基咔唑提供了一种有效的合成途径。该路线导致直接合成两种天然产物,即 clausine E、mukonine 及其 4-异戊二烯类似物。在调查过程中还发现了一条获得环庚 [d,e,f] 咔唑的新途径。