Duphar International Research Bv

Menso P Rappoldt

Louis F Pauli

Jan Hoogendoorn

Gerardus H Mos

The invention relates to the preparation of 9.beta.,10.alpha.-5,7-diene steroids by irradiating the corresponding 9.alpha.,10.beta. steroids with filtered ultraviolet light of an antimony lamp.

Method of preparing 9.beta., 10.alpha.-5,7-diene steroids

The invention relates to a method of preparing .DELTA.5,7-steroids, in particular 7-dehydrocholesterol compounds, of the general formula: ##STR1## wherein R is a hydrogen atom, a hydroxy group, optionally etherified with a C.sub.1 -C.sub.4 alkanol or esterified with a C.sub.1 -C.sub.4 alkane carboxylic acid, a C.sub.2 -C.sub.5 alkanoyl group, optionally ketalized with a C.sub.1 -C.sub.4 alkanol, or a branched or non-branched, saturated or unsaturated C.sub.1 -C.sub.10 alkyl group, optionally substituted with one or more fluorine atoms or hydroxy groups, which hydroxygroup or groups is (are) optionally etherified with C.sub.1 -C.sub.4 alkanol(s) or esterified with C.sub.1 -C.sub.4 alkane carboxylic acid(s), and

Growing community of inventors

Weesp, Netherlands

Menso P Rappoldt