Process comprising the step of reacting a C-22 phenylsulphonyl derivative of cholecalciferol of Formula (2), wherein R1 and R2 are the same or different and represent hydroxyl protecting groups, with a silyl derivative of alfa-hydroxy aldehyde of Formula (3), wherein R3 represents silyl group of formula Si(R4) (R5)(R6), where R4-R6 are the same or different and represent C1-6 alkyl or phenyl groups, in the presence of a strong organic base in aprotic solvent, followed by a reductive desulfonation of the diastereomeric mixture of alfa- hydroxysulfones with sodium amalgam, removing the hydroxyl protecting groups, and purification, leads to calcipotriol containing less than 0,3% of (22Z)-isomer and free of mercury traces.
                            该过程包括以下步骤:在无极性溶剂中,在强有机碱的存在下,将式(2)中R1和R2相同或不同且代表羟基保护基的C-22苯磺酰基
维生素D衍
生物与式(3)中R3代表公式Si(R4)(R5)(R6)的
硅基衍
生物反应,其中R4-R6相同或不同且代表C1-6烷基或苯基,随后通过
钠汞齐还原去除α-羟基磺酮的对映体混合物,去除羟基保护基并纯化,得到含少于0.3%(22Z)-异构体并且不含
汞痕迹的
钙醇三醇。