Patent GB-763198-A (GB)
Title: Substituted phenanthrene compounds and their preparation
IPC: C07D317/72
Filed: 1952-12-19
Abstract: The invention comprises 1,2,3,4,4a,4b,5,6,7, 9,10,10a - dodecahydrophenanthrene - 1,4,7 - trione of the formula <FORM:0763198/IV(b)/1> and the preparation thereof by the acid hydrolysis of a 4b-methyl-1,4-diketo-1,2,3,4,4a,4b,5,6, 7,8,10,10a - dodecahydrophenanthrene which contains in the 7-position a bivalent group or two univalent groups convertible to a keto group by acid hydrolysis, or of a 4b-methyl-1,4-diketo - 1,2,3,4,4a,4b,5,6,10,10a - decahydrophenanthrene which contains in the 7-position a univalent group convertible to keto by acid hydrolysis.  The above processes may be modified in that the starting compound is prepared by a method described and claimed in Specification 763,207.  Further processes for preparing the above compound comprise oxidizing with chromium trioxide 4b-methyl-1,2,3,4,4a, 4b,5,6,7,8,10,10a - dodecahydrophenanthrene - 1,7-dione-4-ol, e.g., prepared by the method described and claimed in Specification 763,197, and by oxidizing with chromic acid the required 1-ol-4,7-dione which has been obtained by the acid hydrolysis of 4b-methyl-1,2,3,4,4a,4b,5,6,7, 8,10,10a - dodecahydrophenanthrene - 1 - ol - 4 - one which is substituted in the 7-position by a bivalent group or two univalent groups convertible to a keto group by acid hydrolysis or of 4b - methyl - 1,2,3,4,4a,4b,5,6,10,10a-decahydrophenanthrene - 1 - ol - 4 - one which contains in the 7-position a univalent group convertible to a keto group by acid hydrolysis.  These processes may be modified in that the starting compounds have been obtained by (1) the incomplete oxidation of the corresponding 1,4-diol as described in Specification 763,207; or (2) by reacting the required 7-substituted-1,4-diol with an acylating agent, e.g. acetic acid in pyridine, to form the corresponding 1-acyloxy-4-hydroxy compound which is then oxidized to the corresponding 1-acyloxy-4-keto compound with pyridine/chromium-trioxide complex and on alkaline hydrolysis the 7-substituted 1-hydroxy-4-keto reactant is formed.  The 7-substituted-1,4-diol reactant used in process (2) above may be prepared by a method described and claimed in Specification 763,208. The 7-position of the compounds used in all the above processes may be substituted by a cyclic ketal or a cyclic thioketal such as an ethylenedioxy, ethylene dithioketal or ethylene henithioketal in the case of a bivalent group convertible to keto by acid hydrolysis, a non-cyclic ketal such as dimethyl ketal in the case of a pair of univalent groups together convertible to a single keto group by acid hydrolysis, and an enol ether group such as ethyl enol ether in the case of a univalent group convertible to keto by acid hydrolysis. Two isomeric 1,4,7-triones of the above formula are referred to having melting-points of 117/117.5 DEG  and 164/166 DEG  C., and the isomer of the latter melting point may be converted into the isomer of the former melting point by treatment with a base, e.g. alkaline alumina.  A further isomer is obtainable from one of the three stereoisomeric forms of 4b - methyl - 1,4 - diketo - 7 - ethylenedioxy - 1,2,3,4,4a,4b,5,6,7,8,10,10a - dodecahydrophenanthrenes referred to in Specification 763,207. A number of detailed examples are given.  Specifications 733,808 and 763,210 also are referred to.