Studies on the syntheses of heterocyclic compounds. 657. Total synthesis of angustine, nauclefine, and gentianine

T Kametani, M Takeshita, M Ihara…

Index: Kametani,T. et al. Journal of Organic Chemistry, 1976 , vol. 41, p. 2542 - 2545

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Citation Number: 20

Abstract

Condensation of 4-methyl-5-vinylnicotinonitrile (7) with ethyl oxalate, followed by acid hydrolysis, gave 3-eth-oxycarbonyl-l-oxo-5-vinylpyrano [4, 3-c] pyridine (lo), which was heated in wet dimethylformamide to afford an unexpected product, gentianine (6). Gentianine (6) was also prepared directly from 7. Condensation of 7 with ethyl formate yielded 3, 4-dehydrogentianine (16). Treatment of the lactone (10) with tryptamine gave ...