Search results
Results From The WOW.Com Content Network
N-Bromosuccinimide or NBS is a chemical reagent used in radical substitution, electrophilic addition, and electrophilic substitution reactions in organic chemistry. NBS can be a convenient source of Br • , the bromine radical.
The Wohl–Ziegler reaction [1] [2] is a chemical reaction that involves the allylic or benzylic bromination of hydrocarbons using an N-bromosuccinimide and a radical initiator. [3] Best yields are achieved with N-bromosuccinimide in carbon tetrachloride solvent. Several reviews have been published. [4] [5]
Structure of N-bromosuccinimide, a common brominating reagent in organic chemistry. Like the other carbon–halogen bonds, the C–Br bond is a common functional group that forms part of core organic chemistry. Formally, compounds with this functional group may be considered organic derivatives of the bromide anion.
Structure of N-bromosuccinimide, a common brominating reagent in organic chemistry. Like the other carbon–halogen bonds, the C–Br bond is a common functional group that forms part of core organic chemistry. Formally, compounds with this functional group may be considered organic derivatives of the bromide anion.
Several reagents can be substituted for bromine. Sodium hypochlorite, [4] lead tetraacetate, [5] N-bromosuccinimide, and (bis(trifluoroacetoxy)iodo)benzene [6] can effect a Hofmann rearrangement. The intermediate isocyanate can be trapped with various nucleophiles to form stable carbamates or other products rather than undergoing decarboxylation.
The classic example is the conversion of glucose to arabinose as shown below. The reaction is named after the German chemist Alfred Wohl (1863–1939). The Wohl degradation. Let's say we have a kiliani-fischer synthesis, it basically removes the row of the C2 carbon, it shortens the carbon chain by one carbon.
Ascorbic acid is prepared in industry from glucose in a method based on the historical Reichstein process. In the first of a five-step process, glucose is catalytically hydrogenated to sorbitol, which is then oxidized by the microorganism Acetobacter suboxydans to sorbose. Only one of the six hydroxy groups is oxidized by this enzymatic reaction.
In common with eukaryotes, prokaryotic electron transport uses the energy released from the oxidation of a substrate to pump ions across a membrane and generate an electrochemical gradient. In the bacteria, oxidative phosphorylation in Escherichia coli is understood in most detail, while archaeal systems are at present poorly understood. [58]