Adipic configuration

P-Lactam Antibiotics.—The tripeptide [as (159)] isolated from Penicillium chry-sogenum151 has been accepted as a likely key intermediate in the biosynthesis of penicillins with penicillin N (158), the first of the fi -lactams to be formed.152 It has been shown recently that this tripeptide is formed from radio-active L-a-amino-adipic acid, L-valine, and L-cysteine in P. chrysogenum and has the absolute configuration (159).153 Moreover, it has been shown to be a precursor for penicillin... 

Retrofit. Use of adipic acid in an existing lime or limestone system does not require modification of process flow configuration or absorber design therefore, it is particularly suited for retrofit applications. The fact that it may be added at any point in the slurry circuit provides a greater flexibility in the location and installation of a simple solids storage and feed system, a minimal capital investment. 

Table 5 lists the test results of such a lime run, Run 951-2E, using within-scrubber-loop forced oxidation with 1,330 ppm adipic acid. The system configuration used for this run was the same as that shown in Figure 3, except that the oxidizing air was injected into the effluent hold tank (oxidation tank). A single... 

Factorial Test Results. Full or partial factorial tests have been conducted at Shawnee, primarily to investigate the effects of adipic acid concentration and pH on SO2 removal. These tests usually lasted 12 hours or longer, including at least 5 to 7 hours of steady-state operation. Scrubber configurations used were venturi alone, spray tower alone, combined venturi and spray tower, and TCA. Limestone was used in all scrubber configurations. Lime was used only with the venturi alone. Only the typical results from the TCA and spray tower tests are presented below to show the degree of effect of pH and adipic acid concentration on SO2 removal. 

In 196146 the initial work on ( —)-(/t)-dimenthyl fumarate (l)47 was revised and a diastereomeric ratio of 78.5 21.5 (15,25) for the aluminum chloride promoted addition to 1,3-butadiene (2) was reported. The absolute configuration was established by degradation of the major cycloadduct 3 to threo-2>,4-dimethyl adipic acid (5). Absence of Lewis acids reverses the sense of chiral induction [d.r. 51.2 48.8 (l/ ,27 )]. These observations are rationalized by means of a modified Prelog model. 

Nevertheless, in certain favourable cases, it has been possible to obtain composition information about polymer mixtures [128], and configuration information relating to relatively simple crystalline polymer systems [129]. The latter case is illustrated (Figure 7.8) by the spectrum of poly(ethylene adipate) where the observed spectrum is more complex than would be expected in the absence of conformational effects. 

Riande et al. (21,22) synthesized the cis and tmns isomers of PCDS as well as the trans isomer of poly(l,4-cyclohexylenedimethylene adipate) (PCDA), and studied their polarity by measurements of dielectric constants and dipole moments. They observed that the trans isomer exhibited lower polarity than the cis one, and that the dipole moment decreased with the number of methylene groups of the diacid unit. The configurational properties of the two PCDS isomers were comparatively examined, both experimentally and theoretically, using the rotational isomeric state model. 

Statistically configured polyester amides are always compostable if they have at least 30 wt.% ester content, regardless of whether their amide contents were introduced to the synthesis via e-caprolactam or AH-salt (adipic acid/hexamethylene diamine) [953]. 

Syntheses via Diacids. The reduction of methyl m-metho y-cinnamate (536) with amalgamated aluminum leads to a mixture of diesters of the meso- and adipic acid in a ratio of 4 3 (Scheme 52) [605-607]. The configuration of the latter was shown by its resolution into antipodes via the brucine salts [605]. The cyclization of the acid chlorides of each of the isomers with subsequent hydrogenolysis of the 6- and 12-oxo groups led to hexahydrochrysene. In this process, the meso-form gave the trans-B/C derivative (540) and the dlAormthe cis-B/C derivative (541) [605],... 

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