Verfahren zur Herstellung von 17-Alkoxymethylen-steroiden

摘要

A process is disclosed for the production of 17-alkoxymethylene steroids of general formula (I) (wherein R1 is a methyl or ethyl group, R2 is an alkyl group with no more than 4 carbon atoms, Q is a methylene group, an ethylene group or an ethylidene group and St is the steroid molecule residue). The process is characterized by the fact that a 17-oxo-steroid of general formula (II) (wherein St, Q and R1 have the meanings already indicated) is allowed to react in hydrocarbon of general formula (III) (wherein R3 and R4 may or may not be identical and can each represent either a hydrogen atom or a methyl group) in the presence of potassium tert. butylate with an (alkoxymethylene) triphenyl phosphonium chloride of general formula (IV) [(C6H5)3P-CH2-OR2]<+>Cl- (wherein R2 has the meaning indicated above).