Glycosyl halides are a very valuable and versatile group of synthetic intermediates widely used in carbohydrate chemistry for the ready functionalization at the anomeric carbon. Thus, glycosyl halides can be easily converted into O-glycosides, C-glycosides, or glycals via the generation of intermediate anomeric carbocations, radicals, or cabanions. Because of their moderate stability, glycosyl ...

Polystyrene resins with varied particle sizes (35 to 350-600 microm) and pore diameters (300-1000 A) were employed to study the effects of immobilization resin particle size and pore diameter on Candida antarctica Lipase B (CALB) loading, distribution within resins, fraction of active sites, and catalytic properties for polyester synthesis. CALB adsorbed rapidly (saturation time </= 4 min) for ...

The regularities of sunflower, rapeseed and flaxseed oils’ triglycerides transesterification by the head fraction ethyl alcohol in presence various catalysts have been investigated. cation exchange resin KU-2-8 H+-form containing an immobilized Cu2+-ions (untreated treated 0,1 M sodium hydroxide solution for 90 min 7 days) were used as catalyst. It was shown that all investigated except untreat...

A single clean, good-yielding, environment-friendly microwave-assisted procedure for O-silylation of uridine with tert-butyldimethylsilyl chloride (TBDMSCl), 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) and potassium nitrate as catalyst under solvent-free conditions is reported. Subsequent silyl ether deprotection accomplished a reusable acidic resin via microwave irradiation. Both the silylation d...

The polymerization of resin adhesives, which is highly nonlinear, is chosen as a process control system. When phenol and formaldehyde are mixed, a sudden and unpredictable heat is produced due to an exothermic reaction, which could cause the deviation of process temperature and hence diminish the product quality. Hence, temperature control is necessary for exothermic batch reactor. The most com...