Strychninolic acid

Strychninolic acid, C2iH220gN2, obtained by reduction of strychninonic acid with sodium amalgam, forms long prisms, m.p. 238°, and yields an acetyl derivative, needles, m.p. 281° eorr.). 

Stryctminic acids, 561 Strychninolic acid, 570 Strychninolone, 570 Strychninonic acid, 570 Strychnolethaline, 372 Strychnoline, 564... 

It has been suggested (61) that the great ease of glycolic acid elimination in the case of strychninolic acid is owing to facilitation of the... 

A stereoelectronic argument (62) would suggest quasi-axial addition leading to the right configuration (XLIV) for dihydrostrychninonic acid. The reduction of strychninonic acid to the epimeric strychninolic acid is governed simply by the more ready accessibility of the outer side of the ketone carbonyl group (62). 

Hydroxydihydrostrychnolone-a (LXIII R = OH), as has been mentioned, easily loses water the reverse reaction, nucleophilic addition of OH to strychninolone-a, occurs as a minor reaction in the alkaline cleavage of strychninolic acid to strychninolone-a and in the base-catalyzed isomerization of strychninolone-a to strychninolone-b (63). 

Sodium amalgam has also been used in many instances to reduce carbonyl groups, as in the important conversion of strychninonic (XXXVIII) into strychninolic acid (XXXIX) (59). Conjugated double bonds have also been reduced, as in the conversion of Hanssen C19 acid (CXXVII) into its dihydro derivative by reduction of the maleic acid moeity (103), the conversion of 11-benzalstrychnine (LVII) into 11-benzylstrychnine (104), and the reduction of isostrychnine-II (XXXVI R = OH) to its 11,12-dihydro derivative (58). 

When 10 g. of strychninolic acid is sh en at room temperature, in a well-stoppered flask, with X]4, niole equivalents of 1 TV sodium hydroxide solution a precipitate of strychninolone-a settles out. The product is collected on a BUchner funnel, washed with water and dried. Crystallization of the crude product (6.S-7.2 g.) from alcohol yields pure strychninolone-a as prismatic crystals. 

Confirmation of the position assigned to the ether oxygen of strychnine (and hence in strychninolic acid) is found in the results of the Beckmann rearrangement of 12-isonitrosostrychnine (12-oximinostrychnine) (C21H21O3N3) (XVIII). Thionyl chloride (also tosyl chloride) causes a rearrangement of 12-isonitrosostrychnine to an isomeric carbamic acid (XIX) and a substituted urea (XX) (20). Hydrolysis of XIX by barium hydroxide affords an aldehydic base (XXI), barium cyanide and barium carbonate, while alkaline hydrolysis of XX yields norstrychninic acid (XXII). This may be interpreted by partial formulas as follows ... 

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