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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 Cl 2 or CCl 4). The product is a vicinal dihalide. This type of reaction is a halogenation and an electrophilic addition.
Dihydroxylation is the process by which an alkene is converted into a vicinal diol. Although there are many routes to accomplish this oxidation, the most common and direct processes use a high-oxidation-state transition metal (typically osmium or manganese). The metal is often used as a catalyst, with some other stoichiometric oxidant present. [1]
Vicinal difunctionalization refers to a chemical reaction involving transformations at two adjacent centers (most commonly carbons). This transformation can be accomplished in α,β-unsaturated carbonyl compounds via the conjugate addition of a nucleophile to the β-position followed by trapping of the resulting enolate with an electrophile at the α-position.
Propane-2,2-diol, an example of a geminal diol. A geminal diol has two hydroxyl groups bonded to the same atom. These species arise by hydration of the carbonyl compounds. The hydration is usually unfavorable, but a notable exception is formaldehyde which, in water, exists in equilibrium with methanediol H 2 C(OH) 2
In 1 H-NMR spectroscopy, the coupling of two hydrogen atoms on adjacent carbon atoms is called vicinal coupling. The coupling constant 3 J represents coupling of vicinal hydrogen atoms because they couple through three bonds. Depending on the other substituents, the vicinal coupling constant is typically a value between 0 and +20 Hz. [2]
In the cases of 1,3-, 1,4-, 1,5-, and 1,6- dihalides, Wurtz-reaction conditions lead to formation of cyclic products, although yields are variable. Under Wurtz conditions, vicinal dihalides yield alkenes, whereas geminal dihalides convert to alkynes. Bicyclobutane was prepared this way from 1-bromo-3-chlorocyclobutane in 95% yield. The reaction ...
An allylic rearrangement or allylic shift is an organic chemical reaction in which reaction at a center vicinal to a double bond causes the double bond to shift to an adjacent pair of atoms: It is encountered in both nucleophilic and electrophilic substitution, although it is usually suppressed relative to non-allylic substitution.
monosub. alkenes 1645 medium 1,1-disub. alkenes 1655 medium cis-1,2-disub. alkenes 1660 medium trans-1,2-disub. alkenes 1675 medium trisub., tetrasub. alkenes 1670 weak conjugated C═C dienes 1600 strong 1650 strong with benzene ring 1625 strong with C═O 1600 strong C═C (both sp 2) any 1640–1680 medium aromatic C═C any 1450