abstract |
An industrially advantageous method for producing a steroid C 17,20 lyase inhibitor represented by the following general formula (I), and a stable form of Reformazki reagent suitable for the production method. A specific β-hydroxyester compound derivative or a salt thereof obtained by a Reformatsky reaction from a specific carbonyl compound is reduced in the presence of a metal hydrogen complex compound and a metal halide, and then subjected to a ring closure reaction. By the general formula (I) Embedded image Wherein each symbol is as defined above. Is obtained. In the Li Reformatsky reaction, it is useful to use a crystal of BrZnCH 2 COOC 2 H stable solution or of a compound represented by 5 (BrZnCH 2 COOC 2 H 5 · THF) compounds represented by 2. [Selection diagram] None. |