Stereoselective syntheses of 1,2-dialkyl-1-phenyl cyclopentanes involving intramolecular carbolithiation of α-thioalkenes
作者:Alain Krief、Benoît Kenda、Bruno Remacle
DOI:10.1016/0040-4020(96)00261-x
日期:1996.5
2-Ethyl-1-methyl-1-phenyl cyclopentane, unavailable by butyllithium-promoted carbocyclisation of the corresponding alkenyl selenide, has been synthesized from 6-methylseleno-6-phenyl-1-phenylthio-1-heptene and 7-methylseleno-7-phenyl-2-phenylthio-2-octene with high stereocontrol at all the three stereogenic centers. Depending upon the solvent used, the derivative in which the methyl- and the phenylthiomethyl
2-Ethyl-1-methyl-1-phenyl cyclopentane, unavailable by butyllithium-promoted carbocyclisation of the corresponding alkenyl selenide, has been efficiently produced using two different strategies involving the carbocyclisation of 6-phenyl-6-methylseleno-1-heptene as the key step.
Stereoselective syntheses of 1,2-dialkyl-1-phenyl-cyclopentanes by intramolecular carbolithiation of vinyl sulfides.
作者:Alain Krief、Benoît Kenda、Bruno Remade
DOI:10.1016/0040-4039(95)01641-t
日期:1995.10
6-Methylseleno-6-phenyl-1-phenylthio-1-heptene and 7-methylseleno-7-phenyl-2-phenylthio-2-octene produce l-phenyl-2-(l′-phenylthioethyl)-cyclopentanes with high stereocontrol at all the three stereogenic centers on sequential reaction with butyllithium and methyl iodide or methanol respectively. Depending upon the solvent used, the derivative in which the methyl-and the phenylthio group are cis (THF)