Search results
Results from the WOW.Com Content Network
2-Bromohexane is the organobromine compound with the formula CH 3 CH(Br)(CH 2) 3 CH 3. It is a colorless liquid. The compound is chiral. Most 2-bromoalkanes are prepared by addition of hydrogen bromide to the 1-alkene. Markovnikov addition proceeds in the absence of free-radicals, i.e. give the 2-bromo derivatives. [2]
RCH=CH 2 + HBr → RCHBrCH 3. Under free radical conditions, the direction of the addition can be reversed. Free-radical addition is used commercially for the synthesis of 1-bromoalkanes, precursors to tertiary amines and quaternary ammonium salts. 2-Phenethyl bromide (C 6 H 5 CH 2 CH 2 Br) is produced via this route from styrene.
The order of reactivity follows that CH 2 > CH 3 > CH: Due to the rearrangement of the double bond, terminal olefins tend to give primary allylic alcohols: Cyclic alkenes prefer to undergo allylic oxidation within the ring, rather than the allylic position at the sidechain.
A halogen addition reaction is a simple organic reaction where a halogen molecule is added to the carbon–carbon double bond of an alkene functional group. [1] The general chemical formula of the halogen addition reaction is: C=C + X 2 → X−C−C−X (X represents the halogens bromine or chlorine, and in this case, a solvent could be CH 2 ...
Ring-closing metathesis (RCM) is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the E-or Z-isomers and volatile ethylene.
H 2 C=CH 2 + HBr → H 3 C-CH 2 Br. Bromoethane is inexpensive and would rarely be prepared in the laboratory. A laboratory synthesis includes reacting ethanol with a mixture of hydrobromic and sulfuric acids. An alternate route involves refluxing ethanol with phosphorus and bromine; phosphorus tribromide is generated in situ. [4]
One attractive feature of the Peterson olefination is that it can be used to prepare either cis- or trans-alkenes from the same β-hydroxysilane. Treatment of the β-hydroxysilane with acid will yield one alkene, while treatment of the same β-hydroxysilane with base will yield the alkene of opposite stereochemistry.
Wittig reactions are most commonly used to convert aldehydes and ketones to alkenes. [1] [2] [3] Most often, the Wittig reaction is used to introduce a methylene group using methylenetriphenylphosphorane (Ph 3 P=CH 2). Using this reagent, even a sterically hindered ketone such as camphor can be converted to its methylene derivative.