19206-87-2

Upstream product

• 615-90-7 2,5-dimethylhydroquinone 
• 556-82-1 3-methyl-2-buten-1-ol 
• 115-18-4 2-methyl-3-buten-2-ol 

Downstream Products

• 67236-68-4 3-(3-hydroxy-3-methyl-butyl)-2,5-dimethyl-1,4-benzoquinone 
• 1311403-13-0 2-bromo-5-(3-hydroxy-3-methylbutyl)-3,6-dimethyl-[1,4]benzoquinone 

Relevant academic research and scientific papers

Vitamin E chemistry. Nitration of non-α-tocopherols: Products and mechanistic considerations

(Chemical Equation Presented) In contrast to the α-form permethylated at the aromatic ring, non-α-tocopherols possess free aromatic ring positions which enable them to act as potent scavengers of electrophiles in vivo and in vitro. In preparation of enzymatic studies involving peroxynitrite and other nitrating systems, the behavior of non-α-tocopherols under nitration conditions was studied. The nitration products of β-, γ-, and δ-tocopherol were identified, comprehensively analytically characterized, and their structure was supported by X-ray crystal structure analysis on truncated model compounds. Even under more drastic nitration conditions, no erosion of the stereochemistry at 2-C occurred. The nitrosation of γ-tocopherol and δ-tocopherol was re-examined, showing the slow oxidation of the initial nitroso products to the corresponding nitro derivatives by air to be superimposed by a fast equilibrium with the tautomeric ortho-quinone monoxime, which only in the case of γ-tocopherol released hydroxyl amine at elevated temperatures to afford the stable ortho-quinone. Mononitration of δ-tocopherol selectively proceeded at position 5. This selectivity can be explained by the theory of strain-induced bond localization (SIBL) to the quinoid nitration intermediates. Bisnitration was only insignificantly disfavored by the first nitro group, so that under normal nitration conditions offering an excess of nitrating species only the bisnitration product was found.

Spirans. Part 14. Regioisomeric Quinone Methides and Spirodimers Related to Tocopherol

Evidence is provided that the quinone methide (5), 3,4-dihydro-2,2,5,8-tetramethyl-7-methylene-2H-benzo-pyran-6(7H)-one, is more, not less, readily formed than its regioisomer, the corresponding 5-methylenebenzopyran-6-one (4), and consequently that 'bond fixation' and allied geometrical constraints (Mills-Nixon effects) cannot be responsible for the regioselective oxidative dimerisation of tocopherol.The quinone methide (5) obtained transitorily by treating 7-chloromethyl-3,4-dihydro-2,2,5,8-tetramethyl-2H-benzopyran-6-ol (11) with hydrogen carbonate ion rapidly forms the corresponding spirodimer (7), 3,3',4,4',8,9-hexahydro-2',2',5,5',7,7,8',10-octamethylbenzodipyran-2-spiro-7'(6'H)-benzopyran-6'-one and trimer (12), which is the main product.The spirodimer (7) reverts to quinone methide (5) near 80 deg C and is, therefore, rapidly transformed into the trimer at this temperature, whereas the regioisomeric spirodimer (6), previously recognised as the product from the oxidations, is stable.The difference in reactivity between the known quinone methide (4) and the new one (5) is thought to be associated with the benzylic methylene groups of the terminal pyran rings.