Enol esters of 2-substituted-3-oxoalkanoates of (Z)-configuration were reduced by bakers' yeast to chiral 2-substituted-3-hydroxyalkanoates. The sy/f-selectivities of this reaction increased compared with those of the reduction of the corresponding racemic keto esters. The reaction mayproceed via an asymmetric hydrolysis of the enol esters, followed by the reduction of the resulting carbonyl gr...

Genetic specificity information ―seen by‖ the transcriptase is in terms of hydrogen bonded proton states, which initially are metastable amino (–NH2) and, consequently, are subjected to quantum uncertainty limits. This introduces a probability of arrangement, keto-amino → enol-imine, where product protons participate in coupled quantum oscillations at frequencies of ~ 10 13 s −1 and are entangl...

A metal ion that attaches to a peptide backbone has the choice of binding to an amide carbonyl oxygen atom or to an amide nitrogen atom by replacement of the amide proton. Coordination to the nitrogen atom is normally accompanied by elimination of the proton, thereby resulting in deprotonation of the ligand. An alternative possibility, not involving deprotonation, is the unusual amide/iminol ta...

We present R2PI, IR–UV and UV–UV double resonance measurements of the guanine–cytosine (G–C) dimer formed in a supersonic jet. We show that there is only one isomer of G–C in the investigated wavelength range from 33200 to 34100 cm . We assigned the observed G–C isomer to a specific structure, based on comparisons of the IR spectra of the G and C monomers with the G–C dimer in the range of the ...

The electronic and molecular structure of 2,6-bis{/V-(2-hydroxyphenyl)iminomethyl}-4methylphenol (hpimp) is clarified from the measurements of electronic absorption and 'H NMR spectra in various solvents and an X-ray diffraction analysis, together with MO calcula­ tions. Electronic absorption bands of hpimp are at 422, 397.9, 359, 341, 294.3, 265.8, and 224 nm in the non-polar solvent cyclohexa...

The study of tautomerics equilibria is vital importance as tautomeric compounds reactivity highly depends on the proportion each tautomer. Herein, equilibrium 3-phenyl-2,4-pentanedione was studied theoretically by b3lyp/6-31+g(d)methods. effect four solvents considered (water, methanol, carbon tetrachloride and Cyclohexane).The takes place through four-membered ring transition state. barrier he...

In this paper, we report the application of the QM/QM hybrid simulation technique to the photoisomerisation reactions of anils (i.e., Schiff bases of salicylaldehyde with aniline derivatives) in the solid state, on the example of the photochromic polymorph of N-salicylidene-2-chloroaniline. By propagating molecular dynamics on a potential energy surface constructed using a combination of time-d...