CRYSTALS OF VITAMIN D DERIVATIVES AND PROCESS FOR THE PREPARATION THEREOF

摘要

The present invention provides crystals of the compound represented by formula (I): <CHEM> ;crystals of a vitamin D derivative which are obtained by purifying a crude or preliminarily purified product of the vitamin D derivative through a reverse phase chromatography and then crystallizing the purified derivative from an organic solvent; novel compounds which are formed during the synthesis of a vitamin D derivative as by-product; and a method for purifying a vitamin D derivative or the precursor thereof. The method of the present invention makes it possible to supply a highly purified vitamin D derivative, especially ED-71, in bulk and steadily. <IMAGE>