Sinomenine methyl ether

Dimethoxy-4 6-dihydroxyphenanthrene (sinomenol) [xc] is obtained when sinomenine [lxxxix] [98-99], and when the three sinomenine methines, [xci], [xoii], and [xcm] [100], are boiled with 66 per cent, potassium hydroxide. It gives a dimethyl ether [dimethyl-sinomenol] [98], also accessible from sinomenine methyl ether [101], and a dibenzoyl-derivative [98], which also results when sinomenine or the achro-methine [xci] is heated with benzoic anhydride at 160° 0. [100-102]. 

Catalytic hydrogenation of codeine proceeds rapidly with saturation of the 7 8 double bond and formation of dihydrocodeine [m, R = OH] [267-9], also obtainable by the electrolytic reduction of codeine [270], the catalytic reduction of neopine [xm] [271], the methylation of dihydromorphine [272], and the catalytic reduction of dihydro-codeinone [xiv] [273]. By the latter method the optical antipode of dihydrocodeine may be prepared from the sinomenine series [274-5] (see Chap. XXVII). Both enantiomorphs can be demethylated to the corresponding dihydromorphines [269, 274-5]. Dihydrocodeine methyl ether is identical with tetrahydrothebaine [276-8] (see Chap. XIII). 

Dihydrothebainone [ix], obtained by the catalytic reduction of thebainone-A [v] [1] and thebainone-B [xm] [13], can be most conveniently prepared by the catalytic reduction of thebaine in acid solution [9-12, 25], and it can also be obtained by the hydrolysis of its two enol ethers (see below). It is a phenolic, ketonic, base, that shows the diazo-reaction in dilutions up to 1 in 2,000,000 [26-27], gives a methyl ether [28], oxime [9], semicarbazone [29], and a benzylidene [30] and piperonylidene [25] derivative. The optical antipode is produced by the sodium amalgam reduction of sinomenine [xxvi] and is known as desmethoxydihydrosinomenine [31]. 

---