Pentaric acids

The products obtained from the deamination of 3-amino-3-deoxyheptonic acids were not obtained pure.198 Oxidation of the products gave acids whose calcium salts had elemental analyses agreeing with those calculated lor the calcium salts of pentaric acids, and Shafizadeh2 suggested that the latter are formed from 3-deoxy-2-heptulosonic acids, which, in turn, result from a rearrangement accompanying deamination. 

There are four pentaric acids and ten hexaric acids ... 

Pentaric acids (sometimes known as hydroxyglutaric) ribaric (meso), xylaric (meso), and D- and L-arabinaric (d- and L-lyxaric). 

Aldaric acids or their derivatives undergo ready epimerization in pyridine. Alkaline treatment of 4-O-methyl-D-glucuronic acid in the presence of air affords 4-O-methyl-D-glucaric and -D-mannaric acids as well as lower O-methylaldaric acids.262 The two diastereo-isomeric 3-deoxy-2-C-(hydroxymethyl)pentaric acids obtained from... 

The 3- and 5-phosphates of D-ribose have both been obtained through the hydrolysis of naturally occurring ribosides. In 1908 Levene and Jacobs122 subjected the barium salt of inosinic acid to acid hydrolysis and obtained a pentose phosphate as its barium salt. Shortly thereafter the same authors78 showed that, under the conditions which normally convert a pentose to a pentaric acid, this phosphate was oxidized only to a phosphorylated D-ribonic acid and it was evident, therefore, that... 

Garcfa-Martfn et al. reported [98] on the AABB polyamides based on these pentaric acids. Two different types of polycondensate were prepared fully sugar-based polyamides (PA-ArAr and PA-XyXy), and polyamides derived from aldaric acids and aliphatic diamines (PA- Ar and PA- Xy, = 6, 8, 12). In all these cases, aregic polymers were formed, since both sugar configurations lack the C2 axis. 

Recently [52], a variety of carbohydrate-based linear homo- and co-polyesters were obtained Irom these pentaric acids by polycondensation reactions (see Section 5.2.2). 

The lactone derivatives (369) prepared from L-glutamic acid (2-amino-2,3,4-trideoxy-L- /ycero-pentaric acid) can be converted into the 5,5-di-C-methylpent-ose derivative (370) by the reactions outlined in Scheme 65. A salient feature of the synthesis is that the chirality of L-glutamic acid is preserved at C-2 of (370). The enone (371) [prepared from 2-(2-furyl)propan-2-ol] has been converted into methyl 2,3-0-isopropylidene-5,5-di-C-methyl-P-DL-ribopyranoside (372) by cis-dihydroxylation (silver chlorate-osmium tetroxide) and stereoselective reduction (lithium aluminium hydride) of the 2,3-0-isopropylidene derivative of the resulting diol. ... 

Hexachlorb-3-fluoropropane (CHCI2CCI2CCI2F). In a 1-1. flask, a mixture of 1160 g. of 1,1,2,2,3,3,3-heptachloropropane and 740 g. of antimony trifluorodichloride is vigorously stirred so that the temperar ture does not exceed 50°. After the mixture has cooled to 30°, it is slowly heated to 130-140° d maintained at this temperature for five hours. It is then cooled, poured into water, washed with hydrochloric acid—to remove antimony salts— then with water, anddried. The yield is 907 g. of reaction product containing approximately 60 g. of 1,1,2,2-tetrachloro-3,3,3-trifluoropropane (b.p. 130°), 315 g. of 1,1,2,2,3-pentar chloro-3,3-difluoropropane (b.p. 168°), and 435 g. of 1,1,2,2,3,3-hexar chloro-3-fluoropropane (b.p. 210°). 

The pentaric (hydroxyglutaric) acids Rre important primarily as reference compounds in structural proofs. They can be prepared by oxidation of the corresponding pentoses with nitric acid. 

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