6890-03-5Relevant academic research and scientific papers
Influence of intramolecular hydrogen bonding on the conformational equilibrium of cis-3-N,N-dimethylaminocyclohexanol compared with trans-3-N,N-dimethylaminocyclohexanol and cis- and trans-3-N,N-dimethylamino-1- methoxycyclohexane
De Oliveira,Ribeiro,Rittner
, p. 513 - 521 (2007/10/03)
1H NMR data show that concentration increase shifts the conformational equilibrium of cis-3-N,N-dimethylaminocyclohexanol (1) (cis-3-DACH) from the 1aa conformer, stabilized by an intramolecular hydrogen bond (IAHB), to the lee conformer [43% (
Stereospecific fragmentation of 3-dimethylaminocyclohexanols upon electron impact ionization
Vais,Mandelbaum
, p. 750 - 754 (2007/10/03)
Stereoisomeric cis- and trans-1-butyl-3-dimethylaminocyclohexanols have been previously reported to exhibit different electron impact (EI) mass spectra. The m/z 100 [C6H14N]+ ion is obtained only from the cis-isomer. The results of a collision-induced dissociation study are inconsistent with the previously proposed protonated dimethylaminocyclobutane structure (ion a) and suggest the N,N-dimethyl-1-butaneimmonium (CH3CH2CH2CH=N+(CH3)2) structure (ion b) for this ion. The mechanistic pathway proposed for this highly stereospecific process involves initial hydrogen migration from the hydroxy group to the radical site at the charged amino group as the stereospecific step, this being possible only for the cis-amino alcohol. The EI mass spectra of the corresponding stereoisomeric methyl ethers exhibit preferential elimination of formaldehyde from the cis-isomer, which is explained by initial hydrogen migration from the methoxy group to the N atom. The unsubstituted cis- and trans-1-methoxy-3-dimethylaminocyclohexanes do not show any stereospecificity in their behavior under EI.
