Desoxycodeine dihydro

Dihydro-electrolytic reduction of desoxycodeine-C [xv] to dihydro-desoxycodeine-B [lxxiv], and dihydro-i/r-codeine-C the structure [lxxhi] by analogy with the sodium and alcohol reduction of desoxycodeine-C to dihydrodesoxycodeine-C [lxxv] sodium and alcohol reductions have a known tendency to effect 1 4 addition of hydrogen to an allylic ether [248, 281, 423]. (Cf. the reduction of thebaine [lxxvii] to dihydrothebaine-< [lxxvih] [265, 405, 424].)... 

This base is formed together with a small quantity of 1 8-dichloro-dihydrocodide by the action of phosphorus pentachloride on dihydro-i/r-codeine-A [xlih] and its epimer dihydroallo- -codeine-A. It is an exceptionally stable substance, being unaffected by electrolytic or socjium and alcohol reduction heating with sodium methoxide under pressure simply causes demethylation to 8-chlorodihydromorphide [19], but prolonged boiling with sodium in cycZohexanol causes loss of hydro-genchloride and production of desoxycodeine-D [lh, R = Me] and a small amount of the demethylated substance, desoxymorphino-D [lii, R = H] [19, 80]. 

Dihydrodesoxycodeine-D [xm], the only non-phenolic dihydro-desoxycodeine, can be prepared by the catalytic hydrogenation of a-chlorocodide [rv] [29], /3-chlorocodide [v, It = Cl] [7, 29], bromocodide [v, R = Br] [29], and desoxycodeine-C [ix] hydrochloride [6], It has also been reported to be formed by catalytic reduction of codeinone oxime [xlii] hydrochloride [30]. Dihydrodesoxycodeine-D methine [xlhi] results from Hofmann degradation of the methiodide [7], and a substance that is presumably the dihydromethine [xliv] is obtained by catalytic reduction of a-chlorocodeimethine [xlv] [26]. 

A base m.p. 130-132° C. obtained by the hydrogenation of dihydro-desoxycodeine-C, when pure has m.p. 144-145° C. and is in fact (/3-) tetrahydrodesoxycodeine [28]. Speyer and Krauss [35] also claimed to have prepared a-tetrahydrodesoxycodeine by the reduction of allo-i/r-chlorocodide, later shown to be /3-chlorocodide [36], but reinvestigation of the reduction revealed the production of only dihydrodesoxycodeine-D and (/3-) tetrahydrodesoxycodeine [21]. The desoxytetrahydro-iji-codeine obtained by the catalytic reduction of tetrahydro-i/<-chlorocodide and stated to be identical with a-tetrahydrodesoxycodeine [35] is too inadequately described to admit identification. 

Proof that the -CH—CO—CH2 system is involved in this reaction and not the aromatic nucleus is provided by the recovery of dihydro-desoxycodeine-D [lxvh] unchanged from the Mannich reaction [82],... 

In a similar way [lxxxii, R = H] was reduced to [xcvxn], which converted by Wolf-Kishner reduction to [xoix],. which in turn was reduced with lithium aluminium hydride and methylated to give dZ-/3-dihydrodesoxycodoine-B methyl ether [c]. The product was compared, by means of the infra-red absorption spectra, with dihydro-desoxycodeine-B methyl ether prepared from dihydrothebainol-B [oi] and with /3-dihydrodesoxycodeine-B methyl ether prepared from /3-dihydrothobainol-B, which is the C-14 epimor of [oi]. The spootra of... 

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