Patent GB-890565-A (GB)
Title: 3-keto-4-pregnenes and method of preparation
IPC: C07J5/00
Filed: 1958-09-23
Abstract: The invention comprises steroid compounds of the general formula <FORM:0890565/IV (b)/1> wherein R represents hydrogen or an alkanoyl radical having 1 to 6 carbon atoms Y-Y1 is a trivalent radical of the formula <FORM:0890565/IV (b)/2> or <FORM:0890565/IV (b)/3> when Y-Y1 represents a <FORM:0890565/IV (b)/4> or <FORM:0890565/IV (b)/5> radical, R1 represents an alkylsulphonyl radical having 1 to 6 carbon atoms or an arylsulphonyl radical, and when Y-Y1 represents a <FORM:0890565/IV (b)/6> R1 represents hydrogen, an alkylsulphonyl radical having 1 to 6 carbon atoms or an arylsulphonyl radical, and the preparation of compounds of the general formula <FORM:0890565/IV (b)/7> wherein R has the above significance and A-B represents a radical of the formula <FORM:0890565/IV (b)/8> or <FORM:0890565/IV (b)/9> lower alkyl (1 to 6 carbon atoms) by reacting a compound of the general formula <FORM:0890565/IV (b)/100> in which R, R1 and A-B have the above significance, with a mild alkaline reagent such as an alkali metal acetate, in the presence of a solvent such as acetic acid, and, if desired, hydrolysing the product to form a compound in which R represents hydrogen, the preparation of compounds of the general formula <FORM:0890565/IV (b)/111> wherein R and Y-Y1 have the above significance and R1 represents an alkylsulphonyl radical having 1 to 6 carbon atoms or an arylsulphonyl radical by treating the corresponding 11-hydroxy compounds with the required sulphonyl halide in the presence of a pyridine-type base and, if desired, when R represents an alkanoyl radical hydrolysing the products to form the corresponding 21-hydroxy compounds, a process for the preparation of compounds of the general formula wherein R has the above significance and R1 represents a hydrogen atom, an alkylsulphonyl radical having 1 to 6 carbon atoms or an arylsulphonyl radical, by treating the corresponding 16a ,17a -epoxy compound with a chromous salt reducing agent such as chromous chloride, bromide or acetate, a process for the preparation of 21 - acetoxy - 11a  - hydroxy - 4, 16 - pregna - diene-3,20-dione by treating 21-acetoxy-16a ,17a -oxido-4-pregnene-3,20-dione with the oxygenating substances produced by growing the micro-organisms Rhizopus nigricans (ATCC 62276), treating the resulting 11a ,21dihydroxy-16a ,17a -oxido-4-pregnene-3,20-dione with acetic anhydride in pyridine, and treating the resulting 21 - acetoxy - 11a  - hydroxy - 16a , 17a  - oxido - 4 - pregnene-3,20-dione with chromous chloride in acetic acid for about five minutes, a process for the preparation of compounds of the general formula <FORM:0890565/IV (b)/121> wherein R represents an alkanoyl radical having 1 to 6 carbon atoms and R1 has the above significance, by treating the corresponding 16-ethylenically unsaturated compounds with a glycol forming reagent such as potassium permanganate or osmium tetroxide and then, if desired, hydrolysing these compounds to form compounds in which R represents hydrogen, and a process for the preparation of compounds of the general formula <FORM:0890565/IV (b)/132> wherein R and R11 represent alkanoyl radicals have 1 to 6 carbon atoms and R1 has the above significance, by treating the corresponding 16a -hydroxy compound with the required alkanoyl anhydride, preferably in the presence of a base such as pyridine at room temperature for about 8 to 24 hours.  Detailed examples are given.