3043-52-5

Upstream product

• 3854-96-4 2,3,4,5,6,6-hexamethylcyclohexa-2,4-dien-1-one 
• 79376-82-2 1,1,2,3,5,6-hexamethyl-4-neopentylcyclohexadienyllithium 
• 2206-69-1 1,3,4,5,6,6-hexamethylbicyclo<3.1.0>hex-3-en-2-one 
• 87-85-4 Hexamethylbenzene 
• 78002-35-4 1,2,3,4,5,6,6-heptamethylbicyclo<3.1.0>hex-3-en-2-ol 
• 75961-59-0 1,1,2,3,5,6-hexamethyl-4-pentylcyclohexadienyllithium 
• 75961-61-4 C₁₇H₂₉Li 
• 99885-89-9 1,2,3,4,6,6-hexamethyl-5-methylenecyclohexa-1,3-diene 
• 593-53-3 Methyl fluoride 
• 74-87-3 methylene chloride 
• 917-64-6 methyl magnesium iodide 
• 14790-04-6 1,2,4,5,6,6-hexamethyl-3-keto-1,4-cyclohexadiene 

Downstream Products

• 917-54-4 methyllithium 
• 56909-25-2 2,3,4,5,6-pentamethylneopentylbenzene 
• 75934-70-2 2-(2,2-Dimethyl-propyl)-1,3,4,5,5-pentamethyl-6-methylene-cyclohexa-1,3-diene 
• 75934-69-9 1-(2,2-Dimethyl-propyl)-2,3,4,4,5,6-hexamethyl-cyclohexa-2,5-dienol 
• 75934-68-8 3-(2,2-Dimethyl-propyl)-1,2,4,5,6,6-hexamethyl-cyclohexa-2,4-dienol 
• 75934-73-5 (1S,6R)-1-(2,2-Dimethyl-propyl)-2,3,4,4,6-pentamethyl-5-methylene-7-oxa-bicyclo[4.1.0]hept-2-ene 
• 75948-84-4 1,1,2,3,5,6-hexamethyl-4-neopentyl-2,4-cyclohexadiene 
• 75948-80-0 1,1,2,3,5,6-hexamethyl-4-neopentyl-2,5-cyclohexadiene 
• 79376-82-2 1,1,2,3,5,6-hexamethyl-4-neopentylcyclohexadienyllithium 
• 75934-67-7 (β-methylbutyl)-pentamethylbenzene 
• 75948-86-6 (β-methylbutyl)-1,1,2,3,5,6-hexamethyl-2,4-cyclohexadiene 
• 75948-82-2 (β-methylbutyl)-1,1,2,3,5,6-hexamethyl-2,5-cyclohexadiene 
• 75961-61-4 C₁₇H₂₉Li 
• 4045-44-7 1,2,3,4,5-pentamethylcyclopentadiene 

Relevant academic research and scientific papers

EFFECT OF THE CRYSTAL ENVIRONMENT ON THE RATE OF CARBOCATIONIC REARRANGEMENTS: DEGENERATE REARRANGEMENTS OF 1,1,2,3,4,5,6-HEPTAMETHYLBENZENONIUM AND 1-PHENYL-1,2,3,4,5,6-HEXAMETHYLBENZENONIUM IONS

The effect of the crystal environment on the rate of degenerate rearrangements of the 1,1,2,3,4,5,6-heptamethylbenzenonium ion, which takes by a 1,2-shift of the methyl group, was studied by the method of labeled atoms. In contrast to the solution, variation of the nature of the anion in the crystalline state leads to a marked change both in the rate constants of the rearrangement and in the Arrhenius parameters (Ea, log A). It was established in the case of 1-R-1,2,3,4,5,6-hexamethylbenzenonium ions (R = CH3, C6H5) that the main factor determining the variation in the rate of the degenerate rearrangements of the carbocations in the transition from the liquid to the crystalline state or with change in the type of crystal is the electrostatic field created by the cation environment. This factor was used to explain the unusual acceleration of the carbocationic rearrangement in the crystalline state compared with the solution, discovered in the case of the 1,1,2,3,4,5,6-heptamethylbenzenonium ion.

1,2,3,4,5,5-Hexamethyl-6-methylenecyclohexa-1,3-diene and 1,2,3,4,4,5-Hexamethyl-6-methylenebicyclohex-2-ene

The title compounds 3 and 5, respectively, have been synthesized.On treatment of 3 with acids rapid isomerization to 2 takes place.Rearrangement of 5 to homofulvene 4 occurs at 60 deg C within 3 hours.

"IPSO" AROMATIC ALKYLATION IN THE GAS PHASE. INTERMEDIACY AND STRUCTURE GASEOUS HEPTAALKYLBENZENIUM IONS

The structure of heptaalkylbenzenium ions has been investigated in the gas phase with complementary techniques, i. e., chemical ionization mass spectrometry, alkylation of hexaalkylbenzenes by radiolytically generated cations, and collisianally induced dissociation mass spectrometry.The results allow us to assign the ?-complex ( Wheland intermedisate ) structure to the free, gaseous heptaalkylbenzenium ions, in agreement with the established structure of their salts in solution and in the solid state.The heptaalkylbenzenium ions represent the charged intermediates of the gas-phase "ipso"-substitution reactions, whose occurence has been demonstrated and whose mechanism is briefly discussed.

Photolysis of heptamethylbenzenonium cation in aqueous acids. Preparation of pentamethylcyclopentadiene

Irradiation of heptamehylbenzenium ion in a variety of aqueous acids using light of wavelength greater than 350 nm leads to the formation of pentamethylcyclopantediene and acetone.In 50percent HBF4 and 70percent HClO4 this photolysis is very clean and can be used as a convenient preparation of pentamethylcyclopentadiene.A mechanism is proposed for the reaction.

Formation of Peralkylcyclohexadienyllithium Compounds

1,1,2,3,5,6-Hexamethyl-4-methylene-2,5-cyclohexadiene (1) reacts with alkyllithium compounds, RLi (R= n-Bu, sec-Bu, and t-Bu), at 2O deg C in hydrocarbon solution or in the presence of ethers or tertiary amines, which act as ligands, to give stable, soluble 1,1,2,3,5,6-hexamethyl-4-alkylcyclohexadienyllithium compounds, 3a-c.On heating, the latter aromatize to pentamethylalkylbenzenes, 4a-c, with extrusion of methyllithium, while on hydrolysis of 3a-c isomeric substituted cyclohexadienes are obtained.The effects have been investigated of varying RLi structure, ligand, and temperature on the rates of addition and aromatization reactions.Ligand metalation by RLi is a significant side reaction.Addition is faster with ligands known to reduce the association of alkyllithium compounds.Aromatization is faster in the presence of THF which favors formation of loose ion pairs and is slower with heavy substitution on the ring.It is proposed that large substituents (neopentyl) destabilize the transition states for aromatization due to steric interactions.