Alcohols containing benzene rings

The alcohol function is found in simple aliphatic molecules, in acyclic and cyclic ter-penes, and in molecules containing benzene rings. Phenols are also contained in this group of aroma chemicals. 

Many aromatic aldehydes (having the -CHO group joined directly to the benzene ring) undergo polymerisation when heated with a solution of potassium cyanide in aqueous ethanol. Thus benzaldehyde gives benzoin, a compound of double function, since it contains both a secondary alcoholic and a ketonic... 

J.M.J. Frechet (C. J. Hawker, 1990) replaced the divergent synthesis by a convergent growth of a dendritic polymer. The repeatedly employed monomer, 5-hydroxymethyl-l, 3-benzenediol, was 1,3-O-dibenzylatcd with 3,5-bis(benzyloxy)benzyl bromide. The resulting benzyl alcohol containing 7 benzene rings was converted to the benzyl bromide which was... 

Lithium metal in ammonia at high concentration (4 M), with an alcoholic proton donor, will reduce the benzene ring of a phenoxide ion. The lithium salt of estrone is reduced under such conditions in 95% yield to a mixture containing 77% of estr-5(10)-ene-3a,17i -diol and 23% of the derived 5(10)-dihydro derivative. 

Reductions of this type were applied to pyridine [442], alkyl pyridines and to many pyridine derivatives alcohols [443], aldehydes [443], ketones [443] and acids [444], In compounds containing both pyridine and benzene rings sodium exclusively reduces the pyridine ring [445]. Pyridine was not reduced by zinc and other similar metals. 

Aromatic monoterpenes which contain a benzene ring like p-cymene 9, car-vacrol 12, thymol 13 and phenylethyl alcohol 14 (Structure 4.4) are common constituents of many essential oils, e.g. oregano (Origanum sp.), thyme (Thymus sp.), savory (Satureja sp.) and rose (Rosa sp.) oils. Another important constituent class of essential oils is phenypropanoids [36]. They are not considered as terpenoids owing to their different biogenetic origins, which will be mentioned later. 

But very little is known of the receptor s south end, so to speak, the geometry of the area where the opposite end of the molecule has to fit. Here, with 2-C-17, there is a secondary butyl group, and this contains an asymmetric carbon atom. But now this center of asymmetry is clear across the benzene ring from the nitrogen, and should certainly be in some entirely new part of the receptor site. Why not make this compound with the R and the S forms in this new and unusual location Why not, indeed Why not call them the right-lane and the left lane of the Nimitz Fortunately, both R and S secondary butyl alcohols were easily obtained, and the synthesis given above for the racemic compound was paralleled for each of these isomers, separately. Is there any chemistry that is different with the specific optical isomers from that which has been reported with the racemic There certainly is for the first step, since the butyl alcohols rather than the butyl bromides must be used, and this first step must go by inversion, and it cannot be allowed any racemization (loss of the optical purity of the chiral center). 

In one of the first papers [7] it was reported that when isatin 7 was heated (100°C, 6 h) with acetophenone 74 in the presence of potassium hydroxide in water and alcohol 2-phenyl-4-quinolinecarboxylic acid (cinchophen) was formed with a yield of 65%. Later on [60-69] the isatins 59, containing substituents in the benzene ring, were used in the Pfitzinger reaction with the same ketone, and the similarly substituted quinolinecarboxylic acids 75 were obtained (Table 2) [12, 14, 28, 31, 60-69],... 

Alcohol An organic compound containing one or more hydroxyl groups (-OH) attached directly to hydrocarbon structures other than benzene rings. 

The ketone could be reduced to two epimeric alcohols dihydro-kopsine-A (CLXXII) resulted with sodium borohydride reduction (100, 109), whereas catalytic hydrogenation gave dihydrokopsine-B (CLXXIV, 100, 104). Both formed only a monoacetate. Kopsine shows no vinyl absorption in the NMR-spectrum and could not be further reduced (except by catalytic hydrogenation of the benzene ring). The molecule therefore contains seven rings, since subsequent evidence excludes a tetrasubstituted double bond. 

In addition to the ozonolysis of alkenes and a few aromatic compounds [93, 104], ozone oxidizes other groups. Thus saturated hydrocarbons containing tertiary hydrogen atoms are converted into tertiary alcohols [105, 106], and some alkenes are transformed into epoxides [107] or a,p-unsat-urated ketones [108], Benzene rings are oxidized to carboxylic groups [109, ethers [110] and aldehyde acetals [111] to esters aldehydes to peroxy acids [772] sulfides to sulfoxides and sulfones [775] phosphines and phosphites to phosphine oxides and phosphates, respectively [775] and organomer-cury compounds to ketones or carboxylic acids [114]. 

One of the most widely used synthetic methods for preparation of the linearly annelated tricycles 205, containing a six-membered aromatic ring A, is the cyclocondensation of anthranilic acids and lactim ethers. - " Cyclocondensations have been carried out without solvent or in solutions in acetone, " alcohol, chloroform, benzene, - - or ethylene glycol monomethyl ether acetate. - Besides lactim ethers, lactim thioethers have been used as reaction partners of anthranilic acids. - ... 

It forms orange needles, which are soluble in alcohol but insoluble in benzene. Its M.P. is above 330° [25]. It yields no phthalic acid on oxidation, and therefore probably contains the third OH-group in the second benzene ring. Isopurpurin is the principal constituent of the commercial alizarin for red. It dyes a fine scarlet red on alumina its iron lake is greyish violet, and of little value. 

Formation of a cyanoformamidine by treatment of a symmetrical diphenylthiourea with potassium cyanide in alcohol containing lead carbonate, reduction with ammonium sulfide, and ring closure with concentrated sulfuric acid to isatin-2-anil also formed smoothly by ring closure of the cyanoformamidine with aluminum chloride in benzene or carbon disulfide. 

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