DETERMINATION OF THE CONFIGURATION OF EPIMERIC DIOLS OF VITAMIN-D3 SERIES BY MASS-SPECTROMETRY

The mass spectral elimination of water in epimeric 1, 3-diols of vitamin D3 (colecalciferol) series has been investigated. It was found that the mass spectra of these stereoisomers differ sharply in the relative intensities of the ions M-H2O (m/e 382) and a-H2O (m/e ± 34), where ion a (formed via formal cleavage of the 7,8-double bond) is characteristic of vitamin D3 and its derivatives. So while epimeric 1,3-diols of vitamin D3 series have very close UV and NMR characteristics, the comparison of the ratios of the peaks M-H2O and M+, a-H2U and a, respectively, makes it possible to distinguish between stereoisomeric 1α, 3β-, 1β, 3β-, 1α,3α- and 1β, 3α-diols using their mass spectra. © 1979.