Trans- cyclohexane

The chemoenzymatic synthesis of the analgesic U-(—)-50,488 [41] and new C2-symmetric bisaminoamide ligands derived from N,N-disubstituted trans-cyclohexane, ,2-diamine [41] has been possible by a CALB-catalyzed resolution using ethyl acetate as solvent and acyl donor [42]. 

Scheme 7.22 Mechanism of the sequential kinetic resolution of trans-cyclohexane-1,2-diamine.

FIGURE 2 Glass transition temperature of a polymer prepared from 3,9- bis ( ethylidene- 2,4,8,10-tetraoxaspiro [ 5,5 ] undecane ) and mixtures of trans-cyclohexane dimethanol and 1,6-hexanediol as a function of mol% 1,6-hexanediol. (From Ref. 13.)... 

FIGURE 8 Cumulative release of methylene blue (o), [1,4 - 14c] succinic acid (a), and polymer weight loss ( ) from polymer discs prepared from 3,9-bis(ethylidene-2,4,8,10-tetraoxaspiro[5,5Jundecane) and a 50 50 mole ratio of trans - cyclohexane dimethanol and 1,6-hexanediol at pH 7.4 and 37°C. Polymer contains 0.1 wt% [1,4 — [succinic anhydride and 0.3 wt% methylene blue. (From Ref. 

FIGURE 13 Cumulative release of -nitroacetanilide (PNAC) from polyester discs prepai ed from 3,9-bis(ethylidene-2,4,8,10-tetraoxas-piro[5,5]undecane) and a 60 10 30 mole ratio of trans-cyclohexane dimethanol, 1,6-hexanediol, and triethylene glycol at pH 7.4 and 37 C. PNAC content 2 wt% (o) 0 mol%, ( ) 0.25 mol%, ( ) 0.50 mol% 9,10-dihydroxystearic acid. (From Ref. 23.)... 

FIGURE 25 HPLC chromatograms of polymer samples hydrolyzed to cleave all ortho ester bonds. Samples were prepared at either 130, 145, or leO C. Polymer prepared from 3,9-bis(ethylidene-2,4,8,10-tetraoxaspiro)5,5]undecane) and a 25 75 mole ratio of trans-cyclohexane dimethanol and 1,6-hexanediol and contained 3 wt% phthalic anhydride and 7.5 wt% cyclobenzaprine hydrochloride (CBP). 

Figure 4.5 A MOF oxidation catalyst based on Cu paddlewheels connected by 1,4-trans-cyclohexane-dicarboxylate ligands (only carboxylate groups are explicitly shown). After oxidation by H2O2, paddlewheels are linked by peroxo bridges (Cu = blue O = red C = gray) [34], (Reproduced by permission of the Royal Society of Chemistry.)...

Retardation by acetic acid itself, which reduces the oxidation rate of trans-cyclohexane-1 2-diol by three orders of magnitude, suggests the existence of a pre-equilibrium... 

Entry 3 involves a catalyst derived from (/ , Trans-cyclohexane- 1,2-diamine. The square planar Cu2+ complex exposes the re face of the dienophile. As with the BOX catalysts, this catalyst has c2 symmetry. 

SOCl2 (208 g, 1.75 mol) is added in one portion to a refluxing solution of TEBA-Cl (0.27 g, l. 2 mmol) and the acid (0.826 mol) in Cl(CH2)2Cl (l. 5 l). The solution is refluxed for a further period of time, and then filtered hot and evaporated to yield the acid chloride, which is purified, if necessary, by chromatography from silica [e.g. trans-cyclohexane-1,4-dicarbonyl chloride (30 min), 96% naphthalene-2,6-dicarbonyl chloride (12 h), 94% biphenyl-4-carbonyl chloride (25 min), 60% biphenyl-4,4 -dicarbonylchlo-ride (16 h), 90%]. 

In connection with our own work on the enzyme-catalysed hydrolysis of cyclohexene epoxide with various fungi we made the unexpected observation that the microorganism Corynesporia casssiicola DSM 62475 was able to interconvert the (1R,2R) and (1S,2S) enantiomers of the product, trans cyclohexan-1,2-dioI 25. As the reaction proceeded the (1R,2R) enantiomer was converted to the (1S,2S) enantiomer [20]. If the racemic trans diol 25 was incubated with the growing fungus over 5 days, optically pure (> 99 % e. e.) (1 S,2S) diol 25 could be isolated in 85% yield. Similarly biotransformation of cis (meso) cycIohexan-1,2-diol 26 yielded the (1S,2S) diol 25 in 41 % (unoptimized) yield (Scheme 11). 

In the cases of cis and trans cyclohexane and cis cyclopentane derivatives, the ring closures gave products 28 and 30 in good yields, whereas, surprisingly, the trans cyclopentane amino alcohol failed to react. An explanation of the different reactivities of cis and trans cyclopentane derivatives is given in Section II,D. 

Preparation of the Cyclic Sulfite of trans-Cyclohexane-l,2-diol [14]... 

Zengel, H.G. (1980) A new phosgene free process for trans-cyclohexane-1,... 

From these results it can be seen that in the hydrogenation of 1,2-dialkylcyclohexenes the expected cis-1,2-dialkylcyclohexane is not the sole product. Similarly, in the hydrogenation of the 1,4-dialky lcyclohexenes where both the cis- and trans-cyclohexanes are expected, the trans-isomer being the thermodynamically more stable, the stereoselectivity varies from metal to metal. Thus with palladium, the cis/trans ratio approaches the equilibrium composition, whereas with platinum and rhodium, the equilibrium composition is never approached. It is also instructive to note that in the palladium-catalysed reactions, hydrogenation is accompanied by extensive alkene isomerisation [220—223], whereas with rhodium and platinum, little or no isomerisation is observed [220,... 

Trans-Cyclohexane - 1,2 diol Dinitrate, pltlts (from- hot ligroin), mp 18-5 - l9°j impact test value 72-85 cm fumes at 1.65°, ignites at 185°5 Bergmann-Junk test 0.67 mg NO evolved/ lg sample Refs 1) Beil —not found 2) W.R. Christian ... 

The Mn(II)-catalysed oxidation of glucose by peroxodisulfate ions occurs via a radical-chain mechanism.26 Kinetics of oxidation of thiodiglycollic acid by (trans-cyclohexane-l,2-diaminc-/V, N, N, /V -tetraacetatolmanganateilJI) have been investigated.27 Oxidations of ketoses and aldoses by manganese(IV) in sulfuric acid media have a first-order dependence on sugar and fractional-order dependence on oxidant.28 A mechanism has been proposed for the oxidation of L-malic acid by Mn(III) pyrophosphate in aqueous acid, involving complex formation and radicals.29... 

Periodic add (or sodium metaperiodate) is often the reagent of choice when the substrate is soluble in an aqueous medium, as in the carbohydrate field an example of its use is to be found in Expt 5.117. Sodium metaperiodate supported on silica gel (Section 4.2.55, p. 454) has been found to effectively oxidise water-insoluble a-diols,106 and its value is illustrated in the preparation of hexanedial (Expt 5.78) from trans-cyclohexane-l,2-diol. 

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