Synthetic intermediates useful for the synthesis of the A ring moiety of vitamin D derivatives, methods for their preparation and methods for their use

摘要

PROBLEM TO BE SOLVED: To produce a new intermediate compound useful for synthesizing the A-ring moiety of a vitamin D derivative, especially the vitamin D derivative having a substituting group at the 2-position. ;SOLUTION: This compound is represented by formula I (R₁ is a 1-7C alkyl which is substituted with OH, a halogen, cyano or an acylamino that is unsubstituted or protected). The compound represented y formula I is obtained by reacting a compound represented by formula II with a compound represented by the formula R₂Br (R₂ is a 1-7C alkyl or a 1-7C alkenyl which is substituted with OH, a halogen, cyano or an acylamino that is unsubstituted or protected). The compound represented by formula I is an intermediate useful when synthesizing the A-ring moiety of a vitamin D derivative having a substituent group at the 2-position, e.g. 2-hydroxyproproxy-1,25-dihydroxyviramin D₃.;COPYRIGHT: (C)1998,JPO