Procedure for obtaining 16 l, 17l metilemodioxipregna alkyl-1,4 - diene-11b, 21-diol-3,20-diones

摘要

16l, 17l-alkyl methyleno - dioxypregna - 1,4-dieno 11b, 21-diol 3,20-dione of formula (I), in which R is 2-5C alkyl, for use in treatment of rhinitis and asthma, is made by reaction of 16a-hydroxy prednisolone with a 1,1-dihalo alkyl cpd. of formula X2CH(CH2)nCH3.