Concise and efficient syntheses of methyl 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate and hygrine

Methyl 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate and hygrine are important biosynthetic intermediates for tropane alkaloids. We have developed a concise method to synthesize these two compounds from the key intermediate N-methylpyrrolinium cation. Methyl 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate and hygrine were obtained in four and six steps from commercially available 4,4-diethoxybutylamine with overall yields of 42% and 25%, respectively. Key words: methyl 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate, hygrine, biosynthetic intermediate, tropane alkaloid, N-methylpyrrolinium cation. Le 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate de methyle et l'hygrine sont des intermediaires biosynthetiques importants pour la synthese des alcaloides tropaniques. Nous avons mis au point une methode pour synthetiser ces deux composes tk;4a partir du cation N-methylpyrrolinium comme intermediaire cle. Nous avons obtenu le 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate de methyle et l'hygrine en quatre et six etapes, respectivement, a partir de la 4,4-diethoxybutylamine, qui est commercialement disponible, avec des rendements respectifs de 42 % et de 25 %. [Traduit par la Redaction] Mots-cles : 4-(1-methylpyrrolidin-2-yl)-3-oxobutanoate de methyle, hygrine, intermediaire biosynthetique, alcaloide tropanique, cation N-methylpyrrolinium.
Introduction Tropane alkaloids, a family of important natural products found in plants throughout the world, have attracted growing attention becauseoftheir significant biological and pharmacological activity. (1-5) These alkaloids contain complex [...]