CRYSTALLOGRAPHIC EXAMINATION OF 14 STRAIGHT CHAIN ALKYL ESTERS OF CHOLESTEROL

The unit cell dimensions and space groups of the common n-alkyl esters of cholesterol (with the exception of the propanoate) have been determined by single crystal X-ray diffraction studies. No overall structural pattern is evident for this series but there are small groups of esters whose structures appear to form regular sequences. Using X-ray powder photography, the crystalline solid phases of the esters obtained from solution were compared with those obtained by cooling the melt. In the majority of cases there are no significant differences but for the methanoate, ethanoate, butanoate, pentanoate and dodecanoate there appears to be solid state polymorphism.