78617-27-3

Upstream product

• 499-75-2 carvacrol 
• 89-83-8 thymol 
• 490-06-2 3-isopropyl-6-methyl-1,2-benzenediol 

Relevant academic research and scientific papers

Structure-Odor Activity Studies on Derivatives of Aromatic and Oxygenated Monoterpenoids Synthesized by Modifying p-Cymene

Thymoquinone was recently reported as having a unique pencil-like odor and being the impact compound for the cedar-like and cedar wood-based product smell such as pencils. The compounds thymol and carvacrol are structurally related odorants commonly found in plants and foods such as thyme and oregano, also having a significant contribution to their overall aroma. However, a systematic elucidation of the sensory properties in this class of oxygenated, aromatic monoterpenoids has not been carried out. To close this gap and gain new insights into structure-odor relationships leading to pencil-like and woody odors, 19 structurally related derivatives of p-cymene starting from thymol and carvacrol were synthesized and characterized. The compounds had odor thresholds ranging from 2.0 ng/L air to 388.8 ng/L air, being lowest for thymol and carvacrol and highest for thymohydroquinone. The compounds smelled mostly thyme-like, oregano-like, and pencil-like with phenolic, earthy, and medicinal variations in their odor character, which could be successfully linked to structural motifs.

4,5-Dimethyl-2-Iodoxybenzenesulfonic Acid Catalyzed Site-Selective Oxidation of 2-Substituted Phenols to 1,2-Quinols

A site-selective hydroxylative dearomatization of 2-substituted phenols to either 1,2-benzoquinols or their cyclodimers, catalyzed by 4,5-dimethyl-2-iodoxybenzenesulfonic acid with Oxone, has been developed. Natural products such as biscarvacrol and lacinilene C methyl ether could be synthesized efficiently under mild reaction conditions. Furthermore, both the reaction rate and site selectivity could be further improved by the introduction of a trialkylsilylmethyl substituent at the 2-position of phenols. The corresponding 1,2-quinols could be transformed into various useful structural motifs by [4+2] cycloaddition cascade reactions.

A Catalyst-Controlled Aerobic Coupling of ortho-Quinones and Phenols Applied to the Synthesis of Aryl Ethers

ortho-Quinones are underutilized six-carbon-atom building blocks. We herein describe an approach for controlling their reactivity with copper that gives rise to a catalytic aerobic cross-coupling with phenols. The resulting aryl ethers are generated in high yield across a broad substrate scope under mild conditions. This method represents a unique example where the covalent modification of an ortho-quinone is catalyzed by a transition metal, creating new opportunities for their utilization in synthesis.

The formation of orthoquinones in the dimethyldioxirane oxidation of phenols

The dimethyldioxirane oxidation of selected phenols provides the corresponding orthoquinones. This conversion proceeds via the related arenediols, which are cleanly oxidized to the quinones by this oxidant.

COMPARATIVE OXIDATION OF PHENOLS WITH BENZENESELENINIC ANHYDRIDE AND WITH BENZENESELENINIC ACID

Oxidation of phenols by benzeneseleninic acid 2 in methylene dichloride leads to the para-quinones, whereas oxidation by benzeneseleninic anhydride 1 is confirmed to afford the corresponding ortho-quinones.Addition of indole, as a phenylselenium (II) trapping agent, inhibits the formation of phenylselenoquinones in the oxidation with 1 or 2.

Oxidation of Phenols, Pyrocatechols, and Hydroquinones to ortho-Quinones using Benzeneseleninic Anhydride

Benzeneseleninic anhydride has been used as a mild oxidising reagent to convert phenols into o-quinones including some examples where the p-position is unblocked.The method is limited to the production of o-quinones which are not susceptible to futher reaction.Pyrocatechols and hydroquinones can also be oxidised to the corresponding quinones in excellent yield using benzeneseleninic anhydride.