Succinate general structure

Preparation of starch succinate or alkenylsuccinates by reaction with succinic anhydride or its derivatives. The general structure of these compounds is... 

Already in 1977 a general structure (Fig. 13.3.1) had been published for carboxylic amides as succinate dehydrogenase inhibitors, a structure that still forms the basis of most modern molecules [1]. 

Fig. 13.3.1. General structure for carboxylic amides as succinate dehydrogenase inhibitors.

The direct reaction of [TCO4] in ethanolic solution with dppe and oxalic acid produces the red Tc" complex [Tc(ox)(dppe)2] (552). Attempts to prepare similar complexes with succinic acid, phthalic acid, or salicylic acid failed, or the complexes were stable in solution only. " Similarly, cationic complexes of Tc" are produced by reaction of the versatile precursor [TcO(OH)(dppe)2] (204) with various dithiocarbamates, which produces several complexes of general formula [Tc(dtc)(dppe)2] (553). For this reaction the reductant formamidine sulphinic acid (510) was required in an alkaline solution. The X-ray crystal structure of [Tc(S2CNMe2)(dppe)2] (554) shows a distorted octahedral geometry. Cyclic voltammetry reveals a reversible reduction wave Tc"/Tc couple at —0.53 V, and a reversible oxidation at +0.3 V for the Tc" /Tc" couple. The same compound (554) was also prepared from the thiourea precursor [TcO(tmtu)4] + (91).The reaction of this precursor in dmf in the presence of dppe produced a mixture of brown [TcO(dtc)(tmtu)2] and the Tc" complex (553). The first compound is probably an intermediate... 

The results obtained show clearly that, although a general improvement in all the thermal properties of the material was obtained, this was relevant only in the presence of high amounts of the cyclic comonomer. This is obviously ascribable to the high intrinsic flexibility of the propylene succinate structure. 

The ring structure of the ribose residue was ascertained" in the same general manner as for adenosine and guanosine. Triacetyl-dihydrouridine was prepared by the hydrogenation of triacetyl-uridine. On simultaneous deacetylation and methylation this was transformed to the fully methylated dihydro-uridine. By simultaneous hydrolysis and oxidation of this product, with hydrobromic acid and bromine, trimethyl -D-ribonolactone was formed, its identity being confirmed by oxidation to meso-dimethoxy-succinic acid. It follows that the ribose component has the furanose ring structure, and that uridine is 3 -D-ribofuranosyl-uracil. 

Polyisobutylene succinic esters - Succinic esters are formed by the reaction of PiBSAs with alcohols [39]. In general, polyols are used which can form different products dependent upon alcohol equivalents and processing conditions. These include the monoester, diester and coupled product. Reaction (7.8), where the PiBSA head group has been modified to a generic structure for simplicity. 

Acid salts of this acid (H Y=HOjC CHj CHj CHj COjH) have been studied by Macdonald (65). The structure of RbHY — the first to be elucidated — is remarkable (66). Its general lay-out is similar to those of the acid malonate and acid succinates, but it has been marshalled into a much trimmer array. The space group is the orthorhombic Cmma (of order 16). As the cell contains only four RbHY units, severe S5nnme-try restrictions are imposed. The Rb+ ions lie on points of 222-symmetry,... 

The effects of dicarboxylate [R(COONa)2] ions on the PNO-catalyzed IPTC reactions of PhCOCl and sodium dicarboxylates in H2O/CH2CI2 medium were investigated on selected dicarboxylate ions including oxalate, malonate, maleate, fumarate, succinate, adipate, nonanedioate, phthalate, isophthalate, and terephthalate [190]. In general, the observed products included mono- and bis-(benzoyloxycarbonyl) compounds, benzoic anhydride, and benzoic acid, which depended on the molecular structure of the dicarboxylate ion. Four types of dicarboxylate ions were classified according to the distribution of products shown as follows ... 

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