Separation optimization for the recovery of phenyl ethyl alcohol

Phenyl ethyl alcohol is a compound that occurs naturally in flower petals and in many common beverages, such as beer. Desire for the floral, rose-like notes imparted by phenyl ethyl alcohol has created a unique niche for this chemical in flavor and fragrance industries. Phenyl ethyl alcohol can be produced by Saccharomyces cerevisiae via bioconversion. Often this method of production results in extremely low yields, thus placing a great deal of importance on recovery and purification of the valuable metabolite. To determine the best method for recovering the chemical, a primary recovery step and a secondary recovery step were developed. The primary recovery step consisted of comparing dead-end filtration with crossflow ultrafiltration. Crossflow ultrafiltration was ultimately selected to filter the fermentation broth because of its high flow rates and low affinity for the product. The secondary recovery step consisted of a comparison of liquid-liquid extraction and hydrophobic resin recovery. The hydrophobic resin was selected because of its higher rate of recovery and a higher purity than the liquid-liquid extraction, the current practice of Brown-Forman.     

Chiral discrimination of ethyl and phenyl N-benzyloxycarbonylaminophosphonates by cyclodextrins

Enantiodifferentiation of N-protected ethyl and phenyl α-aminophosphonates with application of commercially available cyclodextrins as chiral solvating agent was studied by means of nuclear magnetic resonance spectroscopy. Four cyclodextrins (α-CD, β-CD, γ-CD and HP-γ-CD) were chosen due to the differences in the size of their inner cavities and substitution of the rim, which in turn might change the affinity of the compounds analyzed to these chiral selectors. The influence of solution pD and host concentration on the enantiodiscrimination efficiency was also studied. As a result, a methodology for the simple and rapid assessment of the enantiomeric composition of various N-benzyloxycarbonyl-α-aminophosphonates has been elaborated upon. 2D Rotating frame nuclear Overhauser and exchange spectrometry experiments and continuous variation methods were applied for establishing the molecular recognition mechanism and structure of the guest–host assemblies.     

Reactions of glycosylamines with diphenylphosphine oxide and ethyl and phenyl phenylphosphinates

A novel procedure has been proposed for the synthesis of chiral α-aminophosphoryl compounds from glycosylamines and PH compounds (diphenylphosphine oxide and ethyl and phenyl phenylphosphonates) under mild conditions. The reaction is accompanied by dehydration of the carbohydrate moiety in unprotected monosaccharides to form furan ring.     

Addition of amines to ethyl α-fluoroacrylate and phenyl α-fluorovinyl ketone

Conclusions The reaction of diethylamine, piperidine, ethylenimine, and cyclohexylamine with ethyl-fluoroacrylate, and also of ethylenimine with phenyl-fluorovinyl ketone, leads to the addition of the amines to the-fluorovinyl group with the formation of-fluoro--aminopropionic acid derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicneskaya, No. 10, pp. 2362–2363, October, 1975.     

Amending cultures of selenium-resistant bacteria with dimethyl selenone

A possible biological intermediate in the reduction and methylation of selenium oxyanions, dimethyl selenone, was synthesized, and the first experiments involving the amendment of selenium resistant bacterial cultures with this compound are reported. The amount of volatile, reduced selenium-containing species released from these cultures into the headspace is significantly more than that produced in analogous experiments involving sodium selenate amended cultures. Dimethyl selenone is reduced in the presence of dimethyl sulfide and dimethyl disulfide in a complex growth medium, trypticase soy broth with 0.1% nitrate. This reduction occurs whether or not the reduced sulfur compounds are biologically produced.     

Selenium heterocycles. XXIX. Reaction of substituted 2-thioxo-1,3-thiaselenoles with ethyl diazoacetate,ethyl azidoformate and phenyl azide

Reaction of 5-substituted 2-thioxo-1,3-thiaselenoles with ethyl diazoacetate, phenyl azide and ethyl azidoformate afforded 2-substituted ω-carbethoxy-1,4-thiaselenafulvenes (II) , 5-substituted 2-phenylimino-1,3-thiaselenoles (IV) and 5-substituted 2-carbethoxyimino-1,3-thiaselenoles (V) , respectively. The structure of these compounds were confirmed by spectroscopic methods and chemical analysis.     

Interaction of manganese(II) with methyl salicylate ethyl salicylate and phenyl salicylate

The proton ligand stability constants of methyl salicylate, ethyl salicylate and phenyl salicylate and the stepwise stability constants of manganese(II) complexes with these have been determined potentiometrically in aqueous ethanol system 50/50 (v/v) at 25°C at different ionic strengths, viz. 0.050 M, 0.075 M, 0.100 M and at 35 and 45°C at an ionic strength of 0.05 M. The thermodynamic stability constants of the complexes have been evaluated from the various values by extrapolating to zero ionic strength at 25°C. The thermodynamic parameters such as free energy changes (ΔG), enthalpy changes (ΔH) and entropy changes (ΔS) involved have been calculated.     

(2-Nitro ethyl)phenyl and cyanophenyl glycosides from the fruits of Diploclisia glaucescens

Chemical investigation of polar fractions of the methanol extract of the fruits of Diploclisia glaucescens of the family Menispermaceae furnished two new phenyl glycosides, 4-(2-nitroethyl)phenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside, and 4-cyanophenyl-beta-D-xylopyranosyl-(l approximately 6)-beta-D-glucopyranoside.