Process for the production of 16,17-[(cyclohexylmethylen)bis(oxy)]-11,21-dihydroxy-pregna-1,4- dien-3,20-dion or its 21-isobutyrat by transketalisation

摘要

The invention relates to a process for the preparation of 16,17-[(cyclohexylmethylene)bis(oxy)]-11,21-dihydroxypregna-1,4- diene-3,20-dione[11 beta ,16 alpha (R)] and similar compounds, by reaction of an appropri-ate 16,17-ketal with cyclohexanealdehyde.