| abstract |
Preparation of sulfonyl derivatives of cholecalciferol of Formula 1, wherein R 1 is a protective group, preferably a t-butyl(dimethyl)silyl, and R 2 is a heterocyclic group, such as a 2-thiazolyl, a 2-benzothiazolyl, a 1-phenyl-1H-tetrazo-5-yl, a 2-pyridyl, a 2-pyrimidynyl, a 1-isochinolinyl, a 1-methyl-2-imidazyl, or a 4-alkyl-1,2,4-triazo-3-yl, comprises the conversion of the hydroxyl derivative of cholecalciferol into the corresponding sulfide followed by its oxidation to the respective sulfone characterized by the use of a hydroxyl derivative of cholecalciferol as a starting material, in which the triene system is protected as a Diels-Alder adduct, and in particular as an adduct with sulfur dioxide of the Formula 2a. Novel are also the derivatives of Formula 3a and 4a, isolated in the process provided by the invention. |