Structure of 2-(α-hydroxybenzyl)-8-methyl-8-azabicyclo[3.2.1]octan-3-one

Abstract

The unambiguous structure of the title compound (which was formed in the reaction of the lithium enolate of tropinone with benzaldehyde) has been determined to be the exo-anti diastereoisomer. The piperidine ring adopts a flattened-chair conformation with the carbonyl group pushed away from the ethylene bridge. There is an intermolecular hydrogen bond between the hydroxyl group

Determination of the N-invertomer stereochemistry in N-substituted nortropanones and norgranatanones using computational and NMR methods

“…Crystal structures indicated that the N-methyl in tropinone [27] and N-phenyl in the granatanone derivative [28] display the axial configuration in the solid state. The N-methyl configuration in the crystals depended on the derivative and was determined to be equatorial in cocaine [29] and its salts [30] as well as in phenyltropane [31], tropinone aldols [32,33], tropinone aldol tosylhydrazone [21], and granatanone aldols [34], but axial in scopolamine [35]. In some conformational studies of granatane derivatives by NMR methods [36], the N-methyl stereochemistry remained undetermined.…”

The cytotoxic properties and preferential toxicity to tumour cells displayed by some 2,4-bis(benzylidene)-8-methyl-8-azabicyclo[3.2.1] octan-3-ones and 3,5-bis(benzylidene)-1-methyl-4-piperidones

“…In this way, changes in the cytotoxic potencies between 1 and various analogs could be attributed to the topographical, physicochemical and chemical properties of the groups at C2 and C6 per se and the interpretation of the results would not be complicated by changes in the torsion angles θ 1 and θ 2 . X-ray crystallography revealed that the displacement of the C2 and C6 axial hydrogen atoms of various piperidines by a dimethylene bridge afforded 8-azabicyclo[3.2.1]octanes [13,14]. Hence the aim of the present investigation was to prepare a small cluster of prototypic molecules related to 1 which bear C2 and C6 substituents, namely series 2, and to compare their cytotoxic properties with the analogs having both axial protons intact on the C2 and C6 atoms viz series 3.…”

Relative configuration, absolute configuration and absolute structure of three isomeric 8-benzyl-2-[(4-bromophenyl)(hydroxy)methyl]-8-azabicyclo[3.2.1]octan-3-ones

“…A chair conformation of the piperidinone ring is observed in the crystal structures of (II) and (III) (Figs. 2 and 3), as is observed in other N-methyl and N-benzyl derivatives of tropinone and granatanone (Li et al, 1993; Lazny, Wolosewicz, Zielinska et al, 2011; Lazny, Nodzewska, Sidorowicz & Kalicki, 2012; Lazny, Wolosewicz,…”