Hydroquinol

CO. Alkynes will react with carbon monoxide in the presence of a metal carbonyl (e.g. Ni(CO)4) and water to give prop>enoic acids (R-CH = CH-C02H), with alcohols (R OH) to give propenoic esters, RCH CHC02R and with amines (R NH2) to give propenoic amides RCHrCHCONHR. Using alternative catalysts, e.g. Fe(CO)5, alkynes and carbon monoxide will produce cyclopentadienones or hydroquinols. A commercially important variation of this reaction is hydroformyiation (the 0x0 reaction ). 

Chemical Designations - Synonyms 1,4-Benzenediol p-Dihydroxybenzene Hydroquinol Pyrogentisic acid Quinol Chemical Formula 1,4-CjH4(OH)2. 

Synonyms AI3-00072 Arctuvin p-Benzenediol 1,4-Benzenediol Benzohydroquinone Benzoquinol Black and white bleaching cream BRN 0605970 CCRIS 714 Dihydroxybenzene jO-Dlhydroxybenzene 1,4-Dihydroxybenzene p-Dioxobenzene EINECS 204-617-8 Eldopaque Eldoquin HQ Hydroquinol Hydroquinole a-Hydroquinone p-Hydroquinone 4-Hydroxy-phenol p-Hydroxyphenol NC1-C55834 NSC 9247 Quinol p-Quinol Quinone Tecquinol Tenox HQ Tequinol UN 2662 USAF EK-356. 

Synonyms 1,4-Benzenediol 1,4-dihydroxy-benzene p-hydroxybenzene hydroquinol quinol Tecquinol... 

Hydroquinone, Hydroquinol, 1,4-Benzenediol or p-Dihydroxybenzene (Hydrochinon in Ger). See 1,4-Dihydroxybenzene in Vol 5 of Encycl, p D1270-R... 

Synonyms 1,4-benzenediol, hydroquinol, / -dihydroxybenzene Formula C6H602 Stmcture ... 

Trade Names Hydrochinon, Hydroquinol, Quinol, Tecquinol, Hydroquinol. 

Hydroquinone (Quinol, hydroquinol, p-diphenol, dihydroxybenzene, 1,4-benzenediol)... 

Molecular shuttle 154+ consists of a tetracationic cyclophane macrocycle, a linear thread containing two hydroquinol stations and a polyether spacer. The macrocycle binds the stations via n - n and charge-transfer interactions between the electron-poor cyclophane and the electron-rich hydroquinols. As explained above, because both stations are energetically degenerate (they are chemically identical) the macrocyclic unit has no preference for either of them and randomly shuttles between them, in this case at a rate of k = 2360 s 1 in (CDs CO at 34 °C, measured by JH NMR spectroscopy. It was already noted in Stoddart s seminal 1991 paper that including two stations of different binding affinity in the thread could allow a stimuli-induced change of position of the macrocycle in a molecular shuttle. 

Pedro et al. reported the enantioselective synthesis of (,S )-3-hydroxy-3-phenyl-3,4-d i hydroquinol i n - 2 (1 /f)-o n c through an extension of their methodology for the diastereoselective benzylation of (.S )-mandelic acid <07S108>. The reaction commences with the benzylation of dioxolane 90 with substituted o-nitrobenzyl bromides 91 followed by the cyclization of adduct 92 resulting in enantiomerically pure dihydroquinolines 93 in good to high yields. 

Chloroplast lamellae contain different types of quinone. A quinone becomes a semiquinone when one hydrogen atom (H+ + e ) is added (a semiquinone is a free radical because of the presence of an unpaired electron) and a hydroquinone when two are added (a hydroquinone is also called a hydroquinol, or simply a quinol) ... 

The structure of the rearranged methoxy-phenol 27 was easily determined by de-methylation with hydrogen iodide to give the hydroquinol 30. Oxidation affords the red 2,3,4,6-tetraphenylquinone 31, identical to the quinone which was first prepared by Kvalnes, 6> by arylating quinone with aryldiazonium salts. 

Hydroquinidine hydrochloride, 668 Hydroquinine, 669 (metabolite), 955 Hydroquinol, 669 Hydroquinone, 669 HydroSaluric, 663 Hydrotest, 1003 Hydroxo 669 Hydroxocobalamin, 669 Hydroxyacetamidoflunitrazepam, 624 Hydroxyacetanilide, 849 Hydroxyacetohexamide, 314... 

Quinone Oxime.—However, the same compound may be obtained by a wholly different reaction. Quinone is a di-ketone derivative of benzene related to hydroquinol (p. 636). Its constitution by this relationship is as given below. Now when this di-ketone is treated with hydroxyl amine which is the characteristic reagent for aldehydes and ketones, yielding oximes we obtain a mono-oxime as follows ... 

Quinone and Phloroglucinol.—Benzoquinone or quinone (p. 636) is considered a di-ketone derivative of benzene because of its relation to hydroquinol or para-di-hydroxy benzene. It may also be considered as an oxygen derivative of di-hydro benzene. 

H.25) 1,4-Benzenediol, hydroquinone, quinol, hydroquinol, 1,4-dihydroxybenzene, /)-hydroxyphenol [123-31-91... 

HYDROQUINOL (123-31-9) Combustible solid (flash point 329°F/165°C cc). A reducing agent. Violent reaction with strong oxidizers, caustics, sodium hydroxide. May explode on contact with oxygen gas. May be oxidized to quinone at room temperatures in the presence of moisture. 

SYNONYMS p-Benzenediol, 1,4-benzenediol, dihydroxybenzene, hydroquinol, quinol. 

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