Sodium, and alcohols, reduction

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].)... 

The loss of the hydroxyl at C-8 during the sodium and alcohol reduction must occur before or during the opening of the cyclic ether link as both [lxxii] and [lxxhi] are stable under these conditions. The process doubtless proceeds by 1 6-addition of hydrogen to the system... 

CH—CH=CH—CH—OH to give desoxycodeine-A [lxxix], which is known to give [lxxiv] and [lxxv] on sodium and alcohol reduction [281, 425]. (5 6-addition is improbable as it would involve an activating influence of the double bond not found in codeine, and 3 6-addition would yield desoxycodeine-E [lxxx] in which the double bond occupies a position that precludes reduction by sodium and alcohol [423].)... 

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). 

Sodium and alcohol reduction yields the constant-proportion inixtiiro of dihydrodosoxycodeines B [lxxiv] and C [lxxv] and di-liydroallo- -oodoino-C (the opimor of lxxtii) [431]. 

Dihydrodesoxycodeine-A was originally thought to be a definite compound, but is now known to be a mixture of two bases. It is obtained by the sodium and alcohol reduction of desoxycodeine-A [m], a-chlorocodide [iv] [1, 3, 10, 22], and desoxycodeine-C [ix] [3, 10], and can be further reduced catalytically to tetrahydrodesoxycodeine [xiv] [3], It was first stated to yield on degradation a methine base that absorbed two moles of hydrogen on reduction, giving tetrahydrodesoxycodeine dihydromethine (see below) [21], but later attempts to isolate the methine base from the products of degradation were unsuccessful [23]. 

This constant-proportion mixture is also obtained in small amount by the sodium and alcohol reduction of the epimeric pair (/(-codeine [24] and allo-i/j-codeine [xi] [25], and of S-ethylthiocodide [xxxm] [12], Elimination of the group at C-8 presumably proceeds by 1 6-addition of... 

Hydrogenation in neutral or weakly acid solution with a palladium catalyst affords tetrahydro-i/r-codeinone [xxix] [7, 28] which is further reduced by sodium and alcohol to tetrahydro-i/r-codeine [xxx], the latter being obtained directly from i/r-codeinone by sodium and alcohol reduction. In no case do derivatives of allo-[Pg.171]

Catalytic or sodium and alcohol reduction of thebainone-A enol methyl ether [vi] affords a substance initially allotted the structure [ix] as it is different from an isomeric substance obtained by the catalytic reduction of dihydrotbebaine- >, at that time believed to be [n] [3]. It is now clear that this base is in fact dihydrothebainone A°-enol methyl ether [x] and is formed from [vi] by 1 4-addition of hydrogen to the conjugated system. The product of catalytic reduction of dihydrothebaine- must therefore be the isomeric AB-enol methyl ether [ix] produced by saturation of the 8 14-double bond of [iv]. Bentley, Robinson, and Wain [5] have in this way obtained a base different from that obtained by Small and Browning [3], but believe their product is the true dihydrothebainone-A5-enol methyl ether [ix] as it can also be prepared in 98 per cent, yield by the sodium and liquid ammonia reduction of dihydrothebaine [xi] [5]. 

Dihydro thebaine-< absorbs only one mole of hydrogen on catalytic reduction, yielding dihydrothebainone AB-enol methyl ether [ix], which is identical with the product of sodium and liquid ammonia reduction of the non-phenolic dihydrothebaine [x] [5]. (A compound of different melting-point and specific rotation was prepared by Small and Brown-ing [3] by the catalytic reduction of dihydrothebaine-< and allotted the structure [xi] owing to a misconception of the structure of the latter. It is probably a mixture [5].) Dihydrothebainone [xn] is produced by the hydrolysis of [ix] showing that no rearrangement of the thebaine skeleton occurs during sodium and alcohol reduction [5]. 

SchifT s bases A -Arylimides, Ar-N = CR2, prepared by reaction of aromatic amines with aliphatic or aromatic aldehydes and ketones. They are crystalline, weakly basic compounds which give hydrochlorides in non-aqueous solvents. With dilute aqueous acids the parent amine and carbonyl compounds are regenerated. Reduction with sodium and alcohol gives... 

Trimethylene dibromide (Section 111,35) is easily prepared from commercial trimethj lene glycol, whilst hexamethylene dibromide (1 O dibromohexane) is obtained by the red P - Br reaction upon the glycol 1 6-hexanediol is prepared by the reduction of diethyl adipate (sodium and alcohol lithium aluminium hydride or copper-chromium oxide and hydrogen under pressure). Penta-methylene dibromide (1 5-dibromopentane) is readily produced by the red P-Brj method from the commercially available 1 5 pentanediol or tetra-hydropyran (Section 111,37). Pentamethylene dibromide is also formed by the action of phosphorus pentabromide upon benzoyl piperidine (I) (from benzoyl chloride and piperidine) ... 

Hydrocinnamic acid may also be prepared by the reduction of cinnamic acid with sodium and alcohol or with sodium amalgam or with hydrogen in the presence of Adams platinum oxide catalyst (Section 111,150) ... 

Hydroisoquinolines. In addition to the ring-closure reactions previously cited, a variety of reduction methods are available for the synthesis of these important ring systems. Lithium aluminum hydride or sodium in Hquid ammonia convert isoquinoline to 1,2-dihydroisoquinoline (175). Further reduction of this intermediate or reduction of isoquinoline with tin and hydrochloric acid, sodium and alcohol, or catalyticaHy using platinum produces... 

A -Pyrazolines are obtained by the reduction of pyrazoles with sodium and alcohol, by catalytic hydrogenation on palladium or by electrochemical means (B-76MI40402). In some cases the reduction proceeds further yielding pyrazolidines and open-chain compounds. 

Cyclohexylcarbinol has been prepared by the reduction of ethyl hexahydrobenzoate with sodium and alcohol, and by... 

Decamethylene glycol has been prepared by the reduction of dimethyl sebacate and diethyl sebacate with sodium and ethyl alcohol by the reduction of sebacamide with sodium and amyl alcohol and by the reduction of dimethyl sebacate with sodium and liquid ammonia in absolute alcohol. The reduction of esters with sodium and alcohol has also been applied to the preparation of many other glycols. ... 

Diethylaminoethyl alcohol has been prepared by reduction of diethylaminoacetic ester with sodium and alcohol, by the action of ethylene chlorohydrin on diethylamine, and by the action of ethylene oxide on diethylamine. ... 

Diphenylmethane has been prepared with aluminum chloride as a catalyst from methylene chloride and benzene, from chloroform and benzene as a by-product in the preparation of triphenylmethane, and from benzyl chloride and benzene. It has been prepared by the reduction of benzophenone with hydriodic acid and phosphorus, or with sodium and alcohol. It has also been made by heating a solution of benzyl chloride in benzene with zinc dust, or with zinc chloride. The above method is only a slight modification of the original method of Hirst and Cohen. ... 

Support for this suggestion comes from many quarters. Reduction of the jS-carboline anhydro-bases with sodium and alcohol or with tin and hydrochloric acid gives the 1,2,3,4-tetrahydro derivatives, as does catalytic reduction over platinum oxide in an alkaline medium. On the other hand, catalytic reduction with platinum oxide in acetic acid results in the formation of the 5,6,7,8-tetrahydro-j3-carbolinium derivatives (see Section III,A,2,a). It should be noted, however, that reduction of pyrido[l,2-6]indazole, in which the dipolar structure 211 is the main contributor to the resonance hybrid, could not be effected with hydrogen in the presence of Adams catalyst. 

If the a-phellandrene nitrite be heated with an alcoholic solution of potash, it is converted into nitrophellandrene, Ck,Hi5(N02). This bodyis converted by reduction with sodium and alcohol into tetrahydrocarvone, or by less energetic reduction with zinc and acetic acid, into carvotan-acetone. The relationship between these bodies is shown by the following formulas —... 

By the reduction of cedrone by means of sodium and alcohol, there is formed dihydro-isocedrol, CijH gO, boiling at 148° to 151° C. under a pressure of 9-5 mm. When cedrene is heated at 180° to 210° C. with hydriodic acid and red phosphorus, and the product formed is reduced by sodium and alcohol, a body Cj Hjg is obtained, which Semmler describes by the name dihydro-cedrene It boils at 116° to 122° C. under 12 mm. pressure its specific gravity is 0-9052 at 15° C. 

Its low specific gravity indicates that it is an open-chain compound, and from its easy reduction by sodium and alcohol, into dihydroaplotaxene, and by hydrogen and platinum black into normal heptadecane OjjHj,., it is evident that aplotaxene is a tetraolefinic normal chain hydrocarbon. 

Methyl-heptylene carbinol, CjHjgO, has been obtained by the reduction of methyl-heptylene ketone by means of sodium and alcohol. It is-an oil with an odour recalling those of rose and linaloe, and has the following characters —... 

With phosphorus pentachloride it yields myrtenyl chloride, CioHi Cl, which by reduction with sodium and alcohol yields pinene. 

On oxidation with potassium permanganate it yields henzoic acid, and on reduction with sodium and alcohol, it is converted into the tetrahydro-der vative CjgHj O. The constitution of this oxide is probably— ... 

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