- Synthesis of scopin acetate and 6,7-didehydrohyoscyamin. Intramolecular phenylsulfenylation of a nonactivated methylene group of ethyl N-demethyl-3-O-(phenylthio)tropine-N-carboxylate
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The synthesis of scopin acetate (6b) and 6,7-didehydrohyoscyamine (17) was achieved by using tropine (5) as the starting compound. Formal (phenylthio)-radical transfer to the nonactivated 6-position of ethyl N-demethyl-3-O-(phenylthio)tropine-N-carboxylate (9) by irradiation in the presence of hexabutyldistannane is a key step of this synthetic approach, involving ethyl 6,7-didehydro-N-demethyltropine-N-carboxylate (15) as a synthetic intermediate (Schemes 3 and 5). The reaction of 9 with tributylstannane in the presence of ethyl acrylate, as a radicophilic olefin, involves Michael-type alkylation at C(6) of the tropine skeleton affording ethyl N-demethyl-N-(ethoxycarbonyl)tropine-6-propanoate (18) (Scheme 6).
- Petrovi?, Goran B.,Sai?i?, Radomir N.,?ekovi?, ?ivorad M.
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p. 3179 - 3186
(2007/10/03)
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- Synthesis, characterization and pharmacological profile of tropicamide enantiomers
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The synthesis, chemical characterization and antimuscarinic activity of the two enantiomers of tropicamide are reported. Functional (rabbit vas deferens, guinea pig heart (force) and ileum) as well as binding experiments (m1 and m4 human muscarinic receptors expressed in CHO-K1 cells; M2 and M3 receptors of rat heart and submaxillary gland membranes) were used to evaluate the antimuscarinic activity of the enantiomers. The results show that none of the enantiomers is able to significantly discriminate among the receptors studied and therefore do not support the proposal of tropicamide as an M4 (m4) selective agent.
- Dei, Silvia,Bellucci, Cristina,Ghelardini, Carla,Romanelli, M. Novella,Spampinato, Santi
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p. 2147 - 2153
(2007/10/03)
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- Analgesic, antimuscarinic activity and enantioselectivity of the four isomers of 3-quinuclidinyl tropate as compared with the enantiomers of hyoscyamine
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The four stereoisomers of 3-quinuclidinyl tropate (2) were synthesized and their absolute configuration established. The analgesic activity of the four isomers on the hot-plate test and their muscarinic antagonism on rabbit vas deferens (M1), g
- Dei,Bellucci,Gualtieri,Romanelli,Scapecchi,Teodori,Bartolini,Ghelardini
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p. 303 - 309
(2007/10/02)
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