Patent GB-768645-A (GB)
Title: Cyclopentanopolyhydrophenanthrene compounds
IPC: C07J9/00
Filed: 1952-08-01
Abstract: The invention comprises 3-acyloxy (and hydroxy) - 7 - keto - D 8(9) (and D 9(11)) - unsaturated cyclopentano - phenanthrene compounds having at rings B and C the formul  <FORM:0768645/IV(b)/1> and <FORM:0768645/IV(b)/2> and a process for the preparation of 7-ketoD 8(9)- and/or 7-keto-D 9(11)-cyclopentanophenanthrene compounds having at rings B and C the above formul  by treating with an acidic catalyst a solution of a cyclopentanophenanthrene compound of one of the types: (a) a monoepoxide of a D 7,9(11)-cyclopentanophenanthrene compound obtained by the process claimed in Specification 764,321; (b) a dihydroxy substituted cyclopentanophenanthrene compound obtained by the process claimed in Specification 768,646; or (c) a D 8(9)-7,11-dihydroxy-cyclopentanophenanthrene compound obtained by the process claimed in Specification 764,321.  The process may be carried out in an aqueous medium, e.g. an aqueous organic solvent medium. Suitable acidic catalysts are aqueous mineral acids such as hydrochloric and sulphuric acid, p-toluenesulphonic acid, oxalic acid and aluminium hexahydrate. The above process may be modified in that the acidic catalyst is dispensed with and the reaction is carried out by heating a solution of the starting compound in an inert solvent or in a solvent which serves to hydrolyse an acyloxy group in the 3-position, e.g. water.  The above process is useful for the preparation of methyl-3-acetoxy-7-keto-D 9(11)-cholenate from methyl 3-acetoxy-D 7,9(11)-choladienate monoepoxide by heating with acetic anhydride, e.g. at a temperature of about 150 DEG  C., or by heating in the presence of an inert solvent such as xylene, at a temperature of about 150 DEG  C., the preparation of a mixture of 3-hydroxy-7-keto-D 9(11),22-ergostadiene and 3 - hydroxy - 7 - keto - D 8(9),22 - ergostadiene by reacting 3-acetoxy-7,11-dihydroxy-D 8(9),22-ergostadiene or ergosteryl D acetate monoepoxide with an aqueous acidic reagent at a temperature from 20 DEG  to 100 DEG  C. (the mixture may then be chromatographed on acid-washed alumina in a 50 per cent etheracetone solution and acetone added to the eluate to separate 3-hydroxy-7-keto-D 8(9),22-ergostadiene), the preparation of a mixture of 3-hydroxy - 7 - keto - D 9(11),22 - ergostadiene and 3 - hydroxy - 7 - keto - D 8(9),22 - ergostadiene, the latter compound predominating, by refluxing ergosteryl D acetate monoepoxide for approximately 4 hours in aqueous acetone or aqueous dioxane with aqueous sulphuric acid, and adding alcoholic alkali to hydrolyse 3-acetoxy groups not hydrolysed by the acid.  A number of detailed examples are given describing the preparation of the compounds detailed above, the preparation of a mixture of D 8(9)- and D 9(11)-7-keto-dehydrotigogenin, and the preparation of 3-hydroxy-7-keto-D 8(11),22-ergostadiene by treating ergosteryl D monoepoxide with aqueous sulphuric acid and acetone and subjecting the product to chromatography, and the product may then be acetylated to form the 3-acetoxy derivative thereof.  The 2,4 - dinitrophenylhydrazine derivative of a mixture of 3 - hydroxy - 7 - keto - D 8(9),22 (and D 9(11),22)-ergostadiene is referred to. Specification 768,644 also is referred to.