DIOXOLANE DERIVATIVES FOR USE AS CHEMICAL INTERMEDIATES

摘要

The invention is concerned with novel dioxolane derivatives of the formula: I in which Ra is hydrogen or (1-4C)alkyl and Rb is (1-4C)alkyl or phenyl optionally bearing a halogeno substituent; their production; and their use for the manufacture of certain known anti-arthritic acids of the formula: V and, in particular, those acids in which Ra=Rb=methyl or Ra=ethyl and Rb=phenyl, by a novel reduction process. The preferred reduction procedures involve the use of an alkali metal borohydride or cyanoborohydride in the presence of a noble metal catalyst, or the use of an alpha -branched alkyl or cycloalkyl Grignard agent. The use of the derivatives of formula I avoids the need for potentially toxic reagents and reactive intermediates in the previously known processes for the production of the acids of formula V.