36127-17-0Relevant articles and documents
METHOD FOR THE PREPARATION OF N-MONOFLUOROALKYL TROPANES AND THEIR USE
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Page/Page column 14, (2021/07/31)
The present invention relates to a method for the preparation of an N-monofluoroalkyl tropane, a method for the preparation of a trialkyltin tropane, a method for the preparation of an iodinated and/or radioiodinated tropane and the use of the N-monofluoroalkyl tropane as a precursor in the method for the preparation of the trialkyltin tropane and/or the iodinated and/or radioiodinated tropane.
Process for producing optically active tropinonemonocarboxylic acid derivative
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, (2008/06/13)
An optically active tropinonemonocarboxylic acid ester derivative useful as an intermediate for synthesis of optically active tropane derivatives was obtained by reacting succindialdehyde with an organic amine and acetonedicarboxylic acid ester to obtain a tropinonedicarboxylic acid ester derivative, and then subjecting this derivative to enzyme-catalyzed asymmetric dealkoxy-carbonylation. Since anhydroecgonine methyl ester derived from the optically active tropinone-monocarboxylic acid ester derivative by reduction and dehydration had the same direction of optical rotation as in the case of anhydroecgonine methyl ester obtained from natural cocaine, it was proved that the obtained optically active tropinonemonocarboxylic acid ester derivative had the same absolute configuration as that of natural cocaine. The yield of the optically active tropinonemonocarboxylic acid ester derivative from the asymmetric dealkoxycarbonylation was 30 to 50 mol %, and its optical purity was 70 to 97% ee. In addition, it was found that a crystalline optically active anhydroecgonine carboxylic acid ester derivative can be obtained by reducing and then dehydrating the optically active tropinonemonocarboxylic acid ester derivative and that its optical purity can easily be increased by recrystallization.
Stereoselective deprotonation of tropinone and reactions of tropinone lithium enolate
Majewski, Marek,Zheng, Guo-Zhu
, p. 2618 - 2626 (2007/10/02)
Tropinone (6) was deprotonated with lithium diisopropylamide and with chiral lithium amides (18-24) and the resulting enolates (two enantiomers) were treated with electrophiles.The aldol reaction with benzaldehyde and deuteration were both diastereoselective.The former yielded only one isomer (exo, anti) of the aldol 8a; the latter proceeded from the exo face.This selectivity permitted us to probe the deprotonation of tropinone with lithium amides; it was concluded that the reaction involves predominantly the exo axial protons.The reaction of tropinone enolate with ethyl chloroformate led, via a ring opening, to the cycloheptenone derivative 9.The reaction with methyl cyanoformate yielded, in the presence of silver acetate and acetic acid, the β-ketoester 8b; however, in the absence of these additives, and especially when 12-crown-4 was added to the enolate, a ring opening leading to the pyrrolidine derivative 10 occured instead.Deprotonation of tropinone with chiral amides proceeded with modest enantioselectivity.A synthesis of non-racemic anhydroecgonine via this strategy allowed establishing the absolute stereochemistry of deprotonation.