GB908284A - Steroid alkyl ethers and a process for their manufacture - Google Patents

Abstract

The invention comprises alkyl ethers of tertiary steroid alcohols containing an ethinyl group attached to the same carbon atom as the tertiary hydroxyl group in any of the 3-, 17- and 20-positions, and the preparation thereof by alkylating the required free steroid alcohol (a reactive group present must be protected by conversion into an inert functional derivative prior to the alkylation step and may be liberated by a subsequent reaction, e.g. secondary hydroxyl groups and keto groups must be protected such as by conversion into esters or semicarbazones). The steroid reactant may also contain a group which is convertible to a more reactive group following the alkylation step, e.g. a 3-hydroxy group may be converted into a 3-keto group. The steroid ethers may be of the androstane, oestrane or pregnane series. The examples describe the preparation of compounds having a saturated nucleus, having D 4-, D 5-, D 1,4-, D 4,6-D 1,4,6-and D 1,3,5-unsaturation, and having a 6a -methyl substituent by the methods referred to above. In addition, 17a - ethinyl - 17 - methoxy (and ethoxy)-D 4,6-androstadien-3-one are prepared by dehydrogenating 17a -ethinyl-17-methoxy (and ethoxy)-D 5-androsten-3b -ol; 17-ethinyl-6a -methyl-testosterone methyl ether is prepared by converting 17a -ethinyl-17-methoxy-D 5-androsten-3b -ol (or acetate) to 17a -ethinyl-17 - methoxy-5a ,6a -oxido-androstan-3b -ol (or acetate), treating this compound with a methyl Grignard reagent to form 17a -ethinyl-17-methoxy-3b ,5a -dihydroxy-6b -methyl-androstan, converting this compound into 3-keto-6b -methyl-17a -ethinyl-17-methoxy-androstan, and isomerising this compound to the corresponding 6a -methyl compound; and 17a -ethinyl-17-methoxy-D 1,4,6-androstadien-3-one is prepared by dehydrogenating the corresponding D 4- or D 1,4-compound with chloranil.