GB517346A - Manufacture of aldehydes of the cyclopentanopolyhydrophenanthrene series - Google Patents

Abstract

517,346. Cyclopentanopolyhydrophenanthrene aldehydes. SOC. OF CHEMICAL INDUSTRY IN BASLE. July 25, 1938, Nos. 22027 and 22028. Convention dates, July 25, 1937, and July 13,1938. [Class 2 (iii)] Saturated or unsaturated 17-formyl-cyclopentanopolyhydrophenanthrenes are prepared by reducing a saturated or unsaturated 17- carboxylic acid of this series by any one of the methods known to be capable of converting a carboxylic acid group into an aldehyde group involving the use of a reducing agent. Reducing methods mentioned include catalytic reduction of the corresponding acid chloride with intermediate protection of nuclear hydroxy groups, reduction by means of stannous chloride and hydrochloric acid of an imidohalide produced by, convertion of the acid into an acid anilide or substituted acid anilide, followed by the action of phosphorus pentahalide, and by reduction of the acid by means of chromous salts. Starting materials mentioned include compounds of the type of aetiocholane, oestrane, hydro-oestrane, and their sterioisomers. The parent materials may contain substituents in the ring system such as free or substituted hydroxy, carbinol, or amino groups. Also keto groups and their enol derivat.ves. The 17-carbon atom may also carry a hydrogen atom, or a free or substituted hydroxyl group. In an example #<5>-3-acetoxy-aetio cholenic acid is converted in benzene solution into its acid chloride by means of thionyl chloride, which is then reduced in xylene solution by means of hydrogen in the presence of palladiumbarium sulphate catalyst to give #<5>-3-acetoxy- 17-formyl-aetiocholane, which may be saponified to the corresponding 3-hydroxy compound.