GB763197A - Substituted phenanthrene compounds and their preparation - Google Patents

Abstract

The invention comprises 4b-methyl-1,2,3,4,4a, 4b,5,6,7,9,10,10a - dodecahydrophenanthrene-4-ol-1,7-dione, and the 4-acylates thereof, of the formula <FORM:0763197/IV(b)/1> wherein R1 represents a hydroxy or acyloxy group, and the preparation of a 1-keto-4-hydroxy-polyhydrophenanthrene compound by oxidizing a 1,4-dihydroxy-polyhydrophenanthrene compound with N-bromoacetamide, e.g. the above 4-ol-1,7-dione may be prepared from the corresponding 1,4-diol-7-one by this method preferably in the presence of an organic base such as pyridine. The above 4-ol-1,7-dione can also be prepared by either of the following processes which are claimed:-by hydrolysing the corresponding 4-acylate with alkali; and by subjecting to acid hydrolysis a 4b-methyl-1,2,3,4,4a,4b,5,6,7,8,10,10a - dodecahydrophenanthrene - 4 - ol - 1 - one having in the 7-position a bivalent substituent or two univalent substituents convertible to keto by acid hydrolysis or a 4b - methyl - 1,2,3,4,4a,4b,5,6,10,10a - decahydrophenanthrene - 4 - ol - 1 - one having in the 7-position a univalent group convertible to keto by acid hydrolysis. This process may be modified in that the reactant is prepared by a process described in Specification 763,210. Examples of bivalent substituents are cyclic ketal groups such as the ethylenedioxy, ethylene dithioketal and ethylene henithioketal groups, examples of two univalent groups are the non-cyclic ketals such as dimethyl ketal, and examples of a univalent group are enol ether groups such as the ethyl enol ether group in which case the reactant is a 1,2,3,4,4a, 4b,5,6,10,10a - decahydrophenanthrene compound. Suitable reagents for the acid hydrolysis are hydrochloric and sulphuric acids and substances which give rise to acids such as p - toluene - sulphonyl chloride. The 4 - acylates of the above 4-ol-1,7-dione may be prepared by either of the following processes which are claimed:-by acylating the 4-ol-1,7-dione; and by oxidizing a 4b-methyl-1,2,3,4,4a,4b,5,6, 7,9,10,10a - dodecahydrophenanthrene - 1,4 - diol-7-one-4-acylate (which may be obtained by hydrolysing the corresponding 1,4,7-triacylate with methanolic potassium carbonate) with chromium trioxide. The 1,4,7-triacylate for use in the above process may be prepared by a method claimed in Specification 763,209 in which case the resulting 4-acylate derivative of the above 4 - ol - 1,7 - dione may be stereoisomerized by treatment with a mild base such as sodium bicarbonate, pyridine, and alkaline alumina. The preferred acylate, reactants and product in all the processes referred to above are the acetates. A number of detailed examples are given. Specifications 736,307, 763,198, and 763,208 also are referred to.