Abstract
Crystals of cholesteryl δ-monohydrofluoropentanoate (CδHFP), C32H46O2F8, are orthorhombic, space group P212121 with cell dimensions a= 11.278(1), b = 46.511(4), c = 6.207(2)A, and Z = 4. The C(17) cholesterol side chains have in almost fully extended conformation, but the δ-monohydrofluoropentanoate chain bends out of the lath-like cholesterol skeleton by a gauche conformation about C(31)-C(34) bond. Molecular packing in the crystal structure is a unique bilayer structure which may be caused by the bend. The non-existence of a mesophase in CδHFP is explained by the bend of the δ-monohydrofluoropentanoate chain out of the cholesterol skeleton.