The invention relates to precursors of the A-ring of vitamin D, of the formula (I):
in which A, R, R1 and R2 are as defined in the specification.
The invention also relates to a method of preparing compounds (I) comprising the enzymatic asymmetrization of 3,5-dihydroxybenzoic acid derivatives, as well as intermediates of preparation of said compounds.
本发明涉及
维生素D A环的前体,其
化学式为(I):其中A,R,R1和R2如规范中所定义。本发明还涉及一种制备化合物(I)的方法,包括酶催化不对称化
3,5-二羟基苯甲酸衍
生物,以及制备所述化合物的中间体。