Action of Beckmann's chromic acid mixture on some monocyclic terpenes / by T.A. Henry and H. Paget.

  • Henry, Thomas Anderson, 1873-1958
Date:
[1928.]
Catalogue details

Licence: Public Domain Mark

Credit: Action of Beckmann's chromic acid mixture on some monocyclic terpenes / by T.A. Henry and H. Paget. Source: Wellcome Collection.

    6/16 (page 73)
    anilic acid, m. p. 129°. Apart from an observation by Wallach (Annalen, 1900, 313, 354), who gives 85—88°, no melting point lower than 115° seems to have been recorded previously for a-iso- propylsuccinic acid, and we at first thought our acid must be Z-a-Zsopropylglutaric acid, for which m. p.’s 92° to 97° have been recorded and from which on one occasion Wallach prepared an anilic acid, [a]D — 24*2°, m. p. 129° (Annalen, 1911, 379, 189), although this derivative is stated by Semmler (loc. cit.) to melt at 159°. To make sure of this point, we resolved dZ-a-Zsopropyl- succinic acid into its optical antipodes. The two optically active forms obtained melted at 94°, and had [a]D=t 23° (approx.). The anilic acid of the cZ-form had m. p. 129°. Mixtures of our acid with (a) the d-form and (6) the Z-form melted at 117° and 94°, respec¬ tively, and a mixture of our anilic acid with that from the (Z-acid at 142°. There can be no doubt, therefore, that the acid produced directly and indirectly by the oxidation of Z-a-phellandrene is Z-a-Zsopropylsuccinic acid. In addition, a small quantity of the racemic acid was obtained, probably due to some racemisation of the Z-phellandrene. In view of these facts, it seems possible that occasionally a-iso- propylsuccinic acid has been mistaken for a-Zsopropylglutaric acid. Thus in Wallach’s case (loc. cit.) the original acid melted at 92—93° and had [a]D — 15*82°, but on treatment of its anhydride with aniline it yielded two anilic acids, melting at 153—155° and 129°, respectively. Only the former was analysed and gave good results for isopropylglutaranilic acid. The second anilic acid had [a]D — 24*2°, and it seems quite likely that it was a-Zsopropylsuccinanilic acid and that the acid, m. p. 92—93°, was a mixture. CMe CHMe CMe HO^^iCH H9C,/\CH-0H v HC,^\>OH HClJ^JCHg * HO-HCl^jCHg > HO-C^'lCH CHPr0 CHPr# CPr^ COMe co2h CO„H co2h COMe /o&> _v i(VCH2 ^ h2c/ ,co2h HCV-^JCH l ch2 -> 1 <r CHPr# i oc<^3ch2 ^ oV OC<^jCHs CHPr0 CHPr0 co2h CHPr^ CHPr^ (IX.) (X6.) (XIII.) (XII.) (XI.) There is also formed from a-phellandrene, in addition to these acids, thymoquinol (XIV) and thymoquinone (XV). The latter CMe HCj^NcO od^JCH CPr£