Optical rotary dispersion studies. 129. Conformational isotope effects and octant contributions of CD/sub 3/ and /sup 13/CH/sub 3/ groups in cyclohexanone

Journal Article · Wed Jul 02 04:00:00 EDT 1980 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00534a035· OSTI ID:7083027

Lee, S F; Edgar, M; Pak, C S; Barth, G; Djerassi, C

Through the variable-temperature circular dichroism measurements of (2S)-2-methyl-d/sub 3/-2-methylcyclohexanone (2) and (2S)-2-methyl-/sup 13/C-2-methylcyclohexanone (4), quantitative values for the conformational isotope effect are obtained. The chair conformation with the heavier isotope in the equatorial position is found to be energetically preferred by 3,4 and 1.5 cal/mol for 3 and 4, respectively, and empirical force-field calculations qualitatively confirm this view. The CD/sub 3/ and /sup 13/CH/sub 3/ groups act as weaker octant perturbers compared to CH/sub 3/.

• Research Organization: Stanford Univ., CA
• OSTI ID: 7083027
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 102:14; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
CARBON 13
CARBON ISOTOPES
CYCLOHEXANONE
DATA
DEUTERIUM
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
HYDROGEN ISOTOPES
INFORMATION
ISOTOPE EFFECTS
ISOTOPES
KETONES
LIGHT NUCLEI
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
OPTICAL ACTIVITY
ORGANIC COMPOUNDS
STABLE ISOTOPES
STEREOCHEMISTRY