Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
α-Substituted Phosphonates. 37. Derivatives of α-Pyrrolomethanephosphonic Acid and N-VinylpyrrolesDiethyl α-aminomethanephosphonate 5a and its α-aryl derivatives 5b-d react with 2,5-diethoxytetrahydrofuran 1 to give diethyl α-pyrrolomethanephosphonate 9a and the α-aryl derivatives 9b-d, respectively. The pyrrolo derivatives 9 can be converted into the lithium salts 15 and 16, respectively, which with carbonyl compounds undergo the HORNER reaction yielding E/Z-mixtures of N-vinylpyrroles 18. In certain cases the intermediate of the HORNER reaction, the β-hydroxyphosphonate 17, can be isolated. The pyrrolo-analogue of stilbene, 18a, is formed only as E-isomer. On treating the lithium salts 15 and 16 with 9 or with alkyl halides α-C-alkylated pyrrolo-phosphonates 22 and 23, respectively, are obtained.
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