Structural modification of steroids through functionalised organolithium compounds
作者:Larry R Falvello、Francisco Foubelo、Tatiana Soler、Miguel Yus
DOI:10.1016/s0957-4166(00)00175-0
日期:2000.6
The reaction of the epoxysteroids 1 and 4, derived from estrone and cholestanone, respectively, with an excess of lithium and a catalytic amount of DTBB (7 mol%) in THF at -78 degrees C, leads to the formation of the corresponding P-oxido-functionalised organolithium intermediates 2 and 5, respectively, which, by reaction with different electrophiles [H2O, D2O, PhCHO, Me2CO, Et2CO, (CH2)(5)CO, CO2] at -78 degrees C to room temperature, afford, after hydrolysis with water? enantiomerically pure compounds 3 and 6, respectively. The stereochemistry of all these compounds was unambiguously determined by correlation with X-ray data for compound 3d and by comparison with the known compound 6a. (C) 2000 Elsevier Science Ltd. All rights reserved.