First example of reversal of normal stereoselectivity in the intramolecular Pauson-Khand reaction
作者:Joseph A. Casalnuovo、Robert W. Scott、Eric A. Harwood、Neil E. Schore
DOI:10.1016/0040-4039(94)88010-7
日期:1994.2
Stereoselectivity favoring exo substituent orientation in the intramolecularPauson-Khandreaction of 3-methyl-4-hydroxy-1,6-heptenynes to form bicyclo[3.3.0]octenones is affected by the relative stereochemistry at C3 and C4. Cycloaddition of one stereoisomer of 3,5-dimethyl-4-propargyl-1,6-heptadiene gives predominantly the bicyclo[3.3.0]octenone isomer containing both substituents in more hindered