108541-48-6Relevant articles and documents
Intramolecular Pyridinium Oxide Cycloadditions: Systematic Study of Substitution, Diastereoselectivity, and Regioselectivity
Lu, Yi,Dey, Patrick N.,Beaudry, Christopher M.
, p. 4028 - 4032 (2021)
Intramolecular pyridinium oxide cycloadditions form complex polycyclic nitrogenous architectures. The diastereoselectivity and regioselectivity of pyridinium oxide cycloadditions was systematically investigated for the first time using complex substrates.
Synthesis of morphan derivatives with additional substituents in 8-position
Stefaowitz, Janine,Schepmann, Dirk,Daniliuc, Constantin,Saito, Susumu,Wünsch, Bernhard
, p. 1057 - 1069 (2016/11/16)
The morphan system (2-azabicyclo[3.3.1]nonane) as a substructure of morphine is of major interest in medicinal chemistry. Herein, the synthesis of morphan derivatives with additional substituents at the propano bridge is reported. In order to avoid the isolation of the smelly and volatile nitrile 6 and the very polar primary amine 9, an efficient one-pot, three-step sequential transformation of the mesylate 5 into amides 10 was developed. The key step of the synthesis was the stereoselective intramolecular opening of the epoxides 11a-d leading to the exo-configured 8-hydroxymorphans 12a-d. The configuration of the exo-configured hydroxymorphan 12d bearing the ?- and s-pharmacophoric 3,4-dichlorophenylacetyl moiety was inverted by oxidation and stereoselective reduction. An X-ray crystal structure analysis of the benzamide 12c confirmed the relative configuration of the hydroxymorphans 12a-d and 14d.
Cycloalkylmethyl Radicals. Part 4. Electron Spin Resonance Study of Conformational Equilibria in Cyclohexenylmethyl and 4-Alkylcyclohexenylmethyl Radicals
Walton, John C.
, p. 1641 - 1646 (2007/10/02)
For cyclohex-2-enylmethyl and 4-alkoxycyclohex-2-enylmethyl radicals the quasi-axial and the quasi-equatorial conformers can both be observed by e.s.r. spectroscopy.Similary, the axial and equatorial conformers of cyclohex-3-enylmethyl radical can be distinguished by e.s.r. spectroscopy.The conformational free-energy difference of the CH2. group in the 2-position, -ΔGdeg300, was found to be 0.17 +/- 0.03 kcal mol-1 and in the 3-position -ΔGdeg300=0.0 +/- 0.1 kcal mol-1.The Arrhenius parameters for inversion of the half-chair conformation of cyclohex-2-enylmethyl radical were determined by lineshape analysis of the exchange-broadened spectra and found to be: log(kf/s-1)=12.3 - (5.7 kcal mol-1)/2.3RT and log(kb/s-1)=12.0 - (5.5 kcal mol-1)/2.3RT.The barrier to rotation about the C.α-Cβ bond in a cyclohexenylmethyl radicals is much less than the barrier in a cyclohexylmethyl radical because the former radical has only one syn-axial hydrogen on C(5) to impede the rotation whereas the latter radical has two syn-axial hydrogens on C(3) and C(5).
