Amides Arndt-Eistert synthesis

Arndt-Eistert synthesis A procedure for converting a carboxylic acid to its next higher homologue, or to a derivative of a homologous acid, e.g. ester or amide. 

The first total synthesis of ( + )-dauricine was reported by Kametani and Fukumoto in 1964 (18,19). Arndt-Eistert reaction of homoveratryl-amine with the acid chloride XIX afforded the amide XXII. Bischler-Napieralski cyclization of the above amide gave the dihydro isoquinoline derivative XXIV, the methiodide of which when reduced with zinc dust and ethanol-hydrochloric acid afforded + )-dauricine. The identity of the synthetic product with ( )-dauricine w as concluded through a comparison of its physical properties (spectra and chromatographic behavior) with those of an authentic sample of the alkaloid. Melting-point determination of a mixture of derivatives of the two specimens is not recorded. 

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