30860-22-1Relevant articles and documents
H chemical shifts in NMR. Part 24? - Proton chemical shifts in some gem-difunctional compounds: 3-endo- and 3-exo-substituted norbornanones
Gauze, Gisele F.,Basso, Ernani A.,Campos, Mateus G.,Rittner, Roberto,Abraham, Raymond J.
, p. 376 - 383 (2007/10/03)
The complete assignment of the 1H and 13C NMR chemical shifts, from 2D techniques and spectra recorded at 500 MHz, for 3-substituted norbornanones with Cl, Br, I, SMe and SeMe substituents at endo and exo positions and 3-exo-hydroxynorbornanone is reported. The observed 1H chemical shifts are compared with the corresponding calculated values using the semi-empirical CHARGE method and ab initio calculations at the B3LYP/6-311++G(d,p) theory level. The molecular geometries were obtained through Density Functional Theory (DFT) methods. Good agreement between the experimental and both sets of calculated values is observed with the CHARGE calculations being more accurate for this series. This illustrates the utility of the CHARGE program for chemical shift assignments and also as a tool for the elucidation of chemical structures. Copyright
OXIDATION OF OLEFINS USING CHROMIC ANHYDRIDE-CHLOROTRIMETHYLSILANE. A CONVENIENT SYNTHESIS OF α-CHLORO KETONES.
Lee, Jong Gun,Ha, Dong Soo
, p. 193 - 196 (2007/10/02)
Disubstituted internal olefins are oxidized selectively to α-chloro ketones in excellent yields from the reaction with chromic anhydride-chlorotrimethylsilane in carbon tetrachloride.
OXYCHLORINATION OF ALKENES BY CHLOROCHROMATE REAGENTS: A FACILE PREPARATION OF α-CHLOROKETONES, AND COMPETITION BY SUBSTITUENT-DIRECTED OXIDATION.
Guerrero, Angel F.,Kim, Ho-jin,Schlecht, Matthew F.
, p. 6707 - 6710 (2007/10/02)
Cyanopyridinium chlorochromate effects a facile preparation of α-chloroketones from simple alkenes, cycloocta-1,5-diene and cyclododeca-1,5,9-triene; 1-methylcaclooct-4-en-1-ol undergoes oxidative cyclization.
Towards a complete account of the mechanism of hydrogen isotope exchange of diastereotopic protons of carbon acids. II. Acid- and base-catalyzed enolization of bicyclohepten-2-ones. Evidence for exchange by inversion
Werstiuk, Nick Henry,Banerjee, Sujit
, p. 534 - 541 (2007/10/02)
A study of acid- and base-catalyzed hydrogen isotope exchange of bicycloheptan-2-one (1a) and its 3-deuteriated analogs has been carried out.We find that the kexo/kendo ratio (658+/-66) for deuteroxide-catalyzed H * D exchange of 1a at C-3 is 7.2 +/- 1.5 times greater than the kexo/kendo ratio (91 +/- 9) for hydroxide catalyzed D * H exchange of 1b.For acid-catalyzed exchange in CH3COOD(H)-D(H)Cl the rate ratios are 156 +/- 20 and 29 +/- 2 for H * D and D * H exchange, respectively.Equations which relate the observed selectivity kexo/kendo (kfast/kslow) to the intrinsic selectivity and the primary, secondary, and solvent KIEs are developed.The differences between the rate ratios for H * D and D * H exchange are interpreted on the basis of a significant contribution of an inversion pathway to exchange of the slow proton (deuteron).The significance of our study - it relates to the mechanism of hydrogen isotope exchange of diastereotopic protons (deuterons, tritons) of any carbon acid - is discussed.
Stereochemistry of acid-catalyzed cleavage of 3-chloro- and 3-bromonortricyclene in deuterated medium. Evidence for edge protonation of nortricyclenes
Werstiuk, Nick Henry,Timmins, George,Cappelli, Frank Peter
, p. 1709 - 1724 (2007/10/02)
Cleavage of 3-chloronortricyclene (4c) and 3-bromonortricyclene (4d) occurs faster than solvolysis in D2SO4-DOAc at 70-75 deg C and yields syn-7-, anti-7-, exo-5-, and endo-5-halo-exo-2-norbornyl acetates as products.That the 7-chloroacetates comprise 70percent of the reaction mixture, that 30percent of the 5-chloro-exo-2-norbornyl acetates which comprised 28percent of the reaction mixture are derived via rearrangement of the syn-7- and anti-7-chloronorbornyl cations, and that the deuterium at C-6 is at least 90percent stereochemically pure endo is evidence that cleavage of the bond farthest removed from the electron withdrawing halogen is preferred 5:1 over the other bonds of the three-membered ring.The stereochemistry of the ring-opening is rationalized on the basis of cleavage via edge-deuteronation with formation of classical halocations as intermediates.The location of deuterium in the 5-halo-exo-norbornyl acetates is used to define the pathways whereby the 5-haloacetates are formed.This study also establishes that C-6 endo deuterated 7-chloro- and 7-bromo-exo-2-norbornyl brosylates can be synthesized from the corresponding 3-halonortricyclenes.
