Codeine methyl ether dihydro

Catalytic reduction of i/i-codeine methyl ether [lxxxi] hydrochloride in acetic acid over platinum oxide gives 77 per cent, dihydro-i/j-codeine-A methyl ether and 16 per cent, tetrahydro- -codeine methyl ether Hodium and alcohol reduction affords almost 100 per cent, dihydro-i/r-o(idoine-C methyl ether, and only traces of dihydrodesoxycodeines [426]. IwtiHS of the group at C-8 is also observed during the sodium and alcohol reduction of 8-othylthiocodido [lxxxii] [427] (see Chap. XVII). 

Alkaline degradation of -codeine methiodide affords e-codeimethine [lxxxih], which resists isomerization [415, 428-9], and this on further degradation gives morphenol and acetylmethylmorphenol [428] (see Chap. VIII). Methine bases have also been prepared from i/r-codeine methyl ether [411, 419], dihydro-i/j-codeine-A [421] and its methyl ether [426], dihydro-i/j-codeine-B [421, 423], dihydro-i/f-codeine-C [295, 423] and its methyl ether [426], tetrahydro- -codeine [295] and its methyl ether [426]. 

Dihydro-y-lsomorphine-3-methyl ether see dihydro-0-codeine-A (Chap. IV). ... 

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). 

Dihydro-0-codeine-A methyl ether. 127 EtOH + EjO plates + 35 25 EtOH 426... 

R = OMe] and on reduction with sodium and alcohol yields dihydro- r-codeine-C methyl ether [xxxix, R = OMe] [53]. Such ethers are readily formed by heating a-chlorocodide with alcohols [52, 54] or with the sodium salts of phenols in alcohol [49, 51]. a-Chloromorphide gives y-isomorphine-8-ethers under similar conditions [55]. 

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