66820-11-9

Upstream product

• 86509-74-2 t-4-t-butyl-c-2,t-6-dimethylcyclohexan-r-1-ol 
• 86509-76-4 Acetic acid (2S,6S)-4-tert-butyl-2,6-dimethyl-cyclohexyl ester 
• 66820-08-4 tert-Butylperoxy-oxo-acetic acid (2R,6R)-4-tert-butyl-2,6-dimethyl-cyclohexyl ester 
• 26348-40-3 t-4-t-butyl-c-2,t-6-dimethylcyclohexyl r-toluene-p-sulphonate 
• 26348-40-3 c-4-t-butyl-c-2,c-6-dimethylcyclohexyl r-toluene-p-sulphonate 
• 86509-76-4 c-4-t-butyl-c-2,c-6-dimethylcyclohexyl r-acetate 
• 86509-74-2 c-4-t-butyl-c-2,c-6-dimethylcyclohexan-r-1-ol 
• 49714-32-1 c-4-t-butyl-r-2,t-6-dimethylcyclohexanone 
• 879-97-0 2,6-dimethyl-4-tert-butylphenol 

Downstream Products

• 66820-12-0 (1R,3S)-1-tert-Butyl-3,5-dimethyl-cyclohexane 

Relevant academic research and scientific papers

Hydrogen shifts in cyclohexylcarbenes. Spatial dependence of activating power and of primary deuterium isotope effects

The conformationally biased ketones 4-t-butyl-cis-2-methylcyclohexanone (1c) and 4-t-butyl-cis-2-trans-6-dimethylcyclohexanone (7a; and its 2,6-dideuterio derivative 7c) were converted into p-toluenesulfonylhydrazone Li salts. Thermolysis or photolysis generated putative singlet carbenes, which underwent competitive axial vs equatorial H shift (or D shift in the case of 7c) to give alkenes. Product analysis showed that a bystander Me(eq) substituent promotes a geminal H shift several times more efficiently than does a bystander Me(ax). This geometry-dependent activating power parallels behavior noted earlier for OMe and Ph bystander groups; but as Me groups are rotationally symmetric and possess no lone pair or π electrons this phenomenon cannot be attributed solely to rotameric considerations or to effects involving mobile electron clouds. For the trans-dimethylcarbenes 10a and 10c the primary deuterium isotope effect (k(H)/k(D)) for axial migration (I(ax)) was determined to be ca. 1.5 times larger than that for equatorial migration (I(eq)). This finding invalidates the common assumption that I(ax) = I(eq) and suggests that published data on deuterium isotope effects and on H(ax)/H(eq) migration selectivities need to be adjusted.

Axial and Equatorial Hydrogen Shifts in Methyl Substituted Cyclohexylidenes. Stereochemically-dependent Isotope Effects and Bystander Assistance

Carbenes were generated from 4-t-butyl-cis-2-methylcyclohexanone (4a) and from 4-t-butyl-cis-2-trans-6-dimethylcyclohexanone (8a, and its corresponding 2,6-d2 analog 8b) by conventional Bamford-Stevens reactions.Product analysis revealed that an equatorial CH3 assists migration of a geminal H more efficiently than does an axial CH3 by a factor of about 4.6.The primary deuterium isotope effect (kH/kD) for axial shift (Iax) is ca. 1.5 times greater than for equatorial shift (Ieq) in the anchored dimethyl substituted carbene 9.

Stereoelectronic Effects in Hydrogen-atom Transfer Reactions of Substituted Cyclohexyl Radicals

Thermolysis of the peroxyoxalates (1)-(7) and the diacyl peroxides (8)-(11) in cyclohexane at 100 deg C gives cycloalkenes and cycloalkanes by hydrogen-atom transfer reactions of the initially formed conformationally biased 4-t-butyl-, 4-t-butyl-cis,cis-2,6-dimethyl-, 4-t-butyl-cis,trans-2,6-dimethyl-, 4-t-butyl-cis-2-methyl-, 4-t-butyl-trans-2-methyl-, and 5-t-butyl-cis-2-methylcyclohexyl radicals (12)-(17).The composition of the product mixtures indicates that transfer of axial β-hydrogen atoms occurs more rapidly than does transfer of equatorial β-hydrogen atoms.These results support the hypothesis that homolytic fission of a C-H bond is favoured when it lies chlose to the plane of an adjacent semi-occupied orbital.