METHOD OF THE PHOTOCHEMICAL ISOMERATION, PHOTOSENSITIZER FOR THIS METHOD AND PROCESS FOR THE PREPARATION THEREOF

摘要

Disclosed is the photochemical conversion of tachysterol compounds into previtamin D compounds and of trans-vitamin D compounds into cis-vitamin D compounds, under the influence of radiation, by exposing a solution of the organic compound to be converted in the presence of a non-polymeric photosensitizer to light with approx. 300 - 1,000 nm wavelength, and by then isolating the resulting product, wherein a substituted thiophene derivative of the general formula (I) having a substantial absorption in said wavelength region is used as the photosensitizer.