D2 D3 METHODS FOR IMPROVED PRODUCTION OF VITAMINS D2 AND D3

摘要

It is an object of the present invention to provide a process for the preparation of vitamin D which imparts improved yield and reduced by-product contamination. In various aspects, this method comprises the preparation of vitamin-D 2 using ergosterol or a dihydroxy derivative thereof as provitamin D 2 as a starting material, or 7-dehydrocholesterol or a dihydroxy derivative thereof as provitamin D 3 . A method for preparing vitamin-D 3 using a derivative as a starting material is provided. The method described herein comprises pre-vitamin-D 2 or pre-vitamin-D 3 by irradiating a starting material in a solution containing an organic base or an inorganic base with light in a wavelength range of 245 to 360 nanometers (nm). obtaining a product and converting the obtained pre-vitamin-D 2 or pre-vitamin-D 3 into vitamin D 2 or vitamin D 3 by heating the product. In various embodiments, these methods further comprise recovering vitamin D 2 or vitamin D 3 from the reaction as a purified product.