Konformation und physikalische daten von alkanen und cyclanen—VI
作者:G. Mann、H. Werner、M. Mühlstädt、W. Engewald
DOI:10.1016/s0040-4020(01)98114-1
日期:1971.1
Three of the five cis-trans-isomeric 1,2,4,5-tetramethylcyclohexanes were prepared stereo- specifically. The remaining two were separated from mixtures and their assignments confirmed. Refractive indices and densities are in linear relationship to the number of gauche-arrangements in the molecule and can be deduced semiempirically. Gas chromatographic retention indices and enthalpies and entropies
reduction of abundant carboxylic acids with molecular hydrogen has been of both practical and theoretical value. We herein report the homogeneous hydrogenation of dicarboxylicacids with the strategy of desymmetrization. Using a rhodium/bisphosphine catalyst, one carboxyl group of meso-diacids was selectively reduced to yield chiral lactones with satisfactory enantioselectivity. This method provides a straightforward