Carbinols group

Work also prepared a series of carbinolamines and polyamines without a quinoline nucleus but, in other respects, conforming in type and range of molecular weight, with quinoline compounds known to possess plasmocidal activity. As none of these were active, it seems clear that the quinoline nucleus in the cinchona alkaloids and in certain synthetic anti-malarials is a potent factor in the production of plasmocidal action. Later the same author made (1942) a series of lepidylamine derivatives of the form R. Q. CHj. NH[CH2] . NEtj, which were found to be inactive, in spite of their similarity to the active examples of the type R. Q. NH[CH2] . NEt2 prepared by Magidson and Rubtzow. Rubtzow (1939) has also shown that an isomeride of dihydroquinine (II) with the quinuclidine nucleus attached via the carbinol group at C in the quinoline nucleus was inactive in an infection of Plasmodium prcecox in finches. 

In view of the identity, so proved, of l-methyl-7-ketopyrrolizidiiie (IX) with retronecanone, it follows that the carbonyl group in the latter must be at C , and that this must also be the position of the secondary carbinol group in retronecine (IV), retronecanol (VIII), deoxyretronecine (XII) and platynecine (V), and also in heliotridine and hydroxyheliotridane, which Adams regards as stereoisomers of retronecine and retronecanol respectively. 

OH group in an axial alignment which, assuming that the anomeric effect in keto-hexoses is of the same magnitude as in aldoses (5), supplements the conformational impact of the equatorial 1-carbinol group.)... 

Figure 3. Hydroxyl PMR signals for p-o-fructopyranose (5) (upper left) and ct-L-gala-heptulose (6) (lower left) in methyl sulfoxide-dtf. 13C NMR spectra of 5 and 6 (in water). The diagonal line relating the 13C-6 resonances of 5 and 6 reflects the large downfield shift attributable to replacement of one H-6 with the 7-carbinol group. 13C chemical shifts for a- and B-o-arabinopyranose (a and b, respectively) (10, 11) are inserted to illustrate the close conformational affinity between 5 and / -, though not a-, d-arabinose (ppm relative to downfield...

The simplest carbohydrates, sometimes referred to as monosaccharides, or sugars, are either polyhydroxyaldehydes (aldoses) or polyhydroxyketones (ketoses). They can be derived from polyalcohols (polyols) by oxidation of one carbinol group to a carbonyl group. For example, the simple three-carbon triol, glycerol, can be converted either to the aldotriose, glyceraldehyde, or to the ketotriose, dihydroxyacetone, by loss of two hydrogens (fig. 12.1). 

A series of polyhydric alcohols, ranging from ethylene glycol to hexitols was examined, at 20° and in the presence of a large excess of lead tetraacetate, by Hockett and coworkers.44 The compounds yielded a family of oxidation-rate curves in which the position of a curve was a function of the number of free carbinol groups in an unbroken series, but there was no simple stoichiometric relation between the number of alcohol groups and the amount of oxidant consumed. At least part of this complexity appeared to be caused by simultaneous oxidation of the formic acid produced in the reaction. The formic acid was converted smoothly to carbon dioxide in about quantitative yield when water was added to the acetic acid solution and the reaction temperature was raised45 - 48 to 35-45°. However, other... 

Some related iV-aryl compounds were examined in model experiments in connection with lead tetraacetate cleavage of samandarin derivatives.194 Oxidation in aqueous acetic acid at 60-70° of 1 -deoxy-1-(p-toluidino)-l-arabinitol (LXXXV) and -D-mannitol yielded two moles of formaldehyde per mole, one mole being derived from the terminal carbinol group and the second from subsequent hydrolysis of the Schiff base (LXXXVI) pro-... 

As depicted in Scheme 13, the SnCU-promoted vinylogous aldol reaction between silyloxy pyrrole 76 and D-glyceraldehyde 11 afforded the unsaturated lactam 77 in a good yield and excellent diastereoselectivity. Saturation of the carbon-carbon double bond within 77 using the NiC /NaBfLt mixture, followed by protection of the free secondary carbinol group as a TBS-ether and TV-Bn for TV-Boc protecting... 

Asymmetric epoxidation Is accomplished by reaction of an allylic alcohol with tert-butyl hydroperoxide In the presence of J)-(-) or L-(+)-dlethyl tartrate and titanium tetralsopropoxlde (Figure la). The orientation of the product can be predicted in advance (-) tartrates epoxldize from the top face of the double bond when the bond Is viewed In a horizontal plane and the carbinol group is on the right, as seen from the front of the plane. The (+) tartrates epoxldize from below the plane (Figure lb). 

Among the three major types of hydroxyl groups in lignin, the phenolic hydroxyl unit (being most acidic) plays a dominant role in alkali-catalyzed reactions (Fig. 14). The a-hydroxyl group, under acidic conditions, is readily transformed into active bcnzylic carbon cations that may undergo a variety of addition or transformation reactions (Fig. 12). The y-carbinol group, when present in phenolic units, is often released as formaldehyde under either acidic (B, Fig. 12) or alkaline (C, Fig. 14) conditions. 

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