Ketones hydroxyl derivatives

This reduction is not as suitable for sterically hindered ketones, since in these cases the alcohol is the major product. The reduction of 11- and 12- " keto steroids, for example, is usually very slow. Furthermore, the 11-keto steroid (76) yields only about 10% of the 11,1 l-d2 labeled analog (77), the main product being the 1 IjS-dj-l la-hydroxyl derivative (78). ... 

The reduction of hydroxy or acetoxy ketones by baker s yeast shows an interesting stereoselectivity. For the reduction of acetylbenzofuran derivatives with baker s yeast, the methyl ketones afforded (S)-alcohol in 20-68% ee. The hydroxyl derivatives afforded (S)-alcohol in 87-93% ee, and the acetoxy derivatives gave (R)-alcohols in 84-91% ee (Figure 8.33) [24bj. 

The second method of preparation (shown in Scheme 2) depends on treating dehydroepiandrosterone (prepared from cholestrol or sitosterol) with acetylene to form the 17a-ethnyl-17p-hydroxy derivative, which is carbonated to the 17a-propionic acid. Reduction of the unsaturated acid in alkaline solution yields the saturated acid, which cyclizes to the lactone on acidification. Bromination to the 5,6-dibromo-compound, followed by oxidation of the hydroxyl group to the ketone, and then dehydro-bromination to the 7a-hydroxyl derivative, produces spironolactone when esterified with thiolacetic acid. 

Study whereas in the aliphatic series only a few compounds of the class are known. The hydroxyl derivatives of the benzene series are of two distinct classes one of which includes true alcohols analogous to those of the aliphatic series, the other includes compounds known as phenols, which are acid compounds. The aldehydes and ketones of the two series are in general formed by similar reactions and are of similar character though in the benzene series a new class, known as quinones, are entirely distinctive. The acids of the benzene series while they may-be prepared by the oxidation of aldehydes as in the aliphatic series are often prepared by the oxidation of a methyl group to carboxyl. 

Derivatives of Pyridine.—(i) Hydroxy pyridines. These compounds may be considered as ketone derivatives of a di-hydro pyridine or as hydroxyl derivatives of pyridine. The two tautomeric formulas thus represent them as follows ... 

Isatin Chloride.— Now isatin which is a di-ketone of di-hydro indole, or the tautomeric form, a mixed ketone and hydroxyl derivative of indole, yields a chloride when treated with phosphorus pentachloride. 

Scheme 8.1 Major estrogens present in Premarin and formation of catechol estrogen metabolites. The 17-ketone analogs are shown. In vivo, they are in equilibrium with the 17-hydroxyl derivatives.

Zahlsen et al. (1993) found that C8-C10 hydrocarbons were extremely well absorbed and their tissue distribution in brain and fat were largely dependent on the number of carbon atoms. -Nonane is one component of JP-8 and it is metabolized at relatively high rates to hydroxyl derivatives, which are converted to the corresponding ketone. Other important hydrocarbons (from a... 

Footnote A Ketones are derived from the fatty acids by the substitution of the hydroxyl of the latter by a monad positive radical. They thus resemble aldehydes in constitution. The best-known ketone is acetone CH 3 CO.CH 3. Mixed ketones are obtained by distilling together salts of two different fatty acids. Thus potassic butyrate and potassic acetate form propyl-methyl-ketone-... 

It had been previously established that quinic acid readily forms a lactone, called quinide. Quinide was shown to have a 7-lactone structure by conversion of the trimethyl ether to 3-hydroxy-4-methoxybenzoic acid (isovanillic acid). At the same time, this reaction established that the hydroxyl at carbon 6 and the carboxyl must be on the same side of the ring. Since the hydroxyl derivative obtained through the Grignard reaction consumes one mole of lead tetraacetate and from the results of the Curtius degradation, it follows that carbon 2 must have both a carboxyl and hydroxyl attached. Furthermore, since the resultant ketone cannot form an osazone, carbons 1 and 3 must be free of hydroxyl groups. By elimination, therefore, the remaining two hydroxyls must be at carbons 4 and 5. Finally, these must... 

With the modified carboxylate-Ru(II) catalyst Ru(02CMes)2(/ -cymene), the hydroarylation of non-unactivated and unstrained alkenes was strongly improved in toluene, even in H2O. Various unactivated alkenes including ether, ketone, hydroxyl, ester, and fluorine functionalized alkenes led to monoalkylated products in moderate to high yields [(Eq. 41)] [125]. This alkylation method could also be applied directly to heterocycles such as indole and thiophene derivatives and proceeded in site-selective manner. 

The reactions leading to 3 -phosphonylated nucleosides require addition of a deprotonated H-phosphonate to the appropriate ketones 45, derived from natural nucleosides (Scheme 47.11). These reactions usually proceed with complete stereoselectivities. " However, a subsequent removal of the a-hydroxyl group under radical reaction conditions... 

Diols that bear two hydroxyl groups m a 1 2 or 1 3 relationship to each other yield cyclic acetals on reaction with either aldehydes or ketones The five membered cyclic acetals derived from ethylene glycol (12 ethanediol) are the most commonly encoun tered examples Often the position of equilibrium is made more favorable by removing the water formed m the reaction by azeotropic distillation with benzene or toluene... 

Neopentyl glycol, or 2,2-dimethyl-1,3-propanediol [126-30-7] (1) is a white crystalline soHd at room temperature, soluble ia water, alcohols, ethers, ketones, and toluene but relatively iasoluble ia alkanes (1). Two primary hydroxyl groups are provided by the 1,3-diol stmcture, making this glycol highly reactive as a chemical intermediate. The gem-A methy configuration is responsible for the exceptional hydrolytic, thermal, and uv stabiUty of neopentyl glycol derivatives. 

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