THE DESOXYCODEINES AND THEIR DERIVATIVES

The name desoxycodeine should logically be applied only to the substance of structure [i], in which the alcoholic oxygen of codeine [n] has been eliminated it is, however, also applied to two isomers of [i] differing in the position of the double bond, and to a phenolic base [m] having an additional double bond in ring C. 

Desoxycodeine-A [m] was first prepared by Knorr and Waentig [1] (and called simply desoxycodeine) by reducing a-chlorocodide [iv] with zinc-dust and alcohol, a process that must involve 1 4-addition of 

Desoxycodeine-A is phenolic, being soluble in alkali, giving a colour with ferric chloride and forming a methyl ether [1]. The phenol may be degraded to a methine base [vi, R = H], which oxidizes rapidly in air, and the methyl ether to [vi, R = Me], which decomposes spontaneously to an amine and dimethylmorphol [vn] [1], 

Reduction of desoxycodeine-A with sodium and alcohol gives a mixture of dihydrodesoxycodeines-B and -C [1] and catalytic hydrogenation affords tetrahydrodesoxycodeine [4] (see below). 

Bromination of the aromatic nucleus occurs when desoxycodeine-A is treated with bromine, and the hydrogen bromide thus formed adds (1 4 ) to the diene system, giving dibromodihydrodesoxycodeine, also obtained by addition of hydrogen bromide to desoxycodeine-A followed by bromination. Acetolysisofthe dibromide yields l-bromo-3-methoxy-4-acetoxyphenanthrene (structure proved by conversion to the 3 4-dimethoxycompound and synthesis of the latter), also prepared by the degradation of 1-bromocodeine [5]. 

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