Stereospecific Reactions

This article Stereospecific Reactions mentions properties and their types based on mechanism and starting material stereochemistry. What are the properties of Stereospecific reactions? Different types of Stereospecific reactions? E2 eliminations from cyclohexanes EXAMPLE 1 Reactant stereochemistry: equatorial substituted cyclohexane Mechanism: anti-periplanar transition state Product stereochemistry: No product Reason: equatorial C-X anti-periplanar to two equatorial C-C […]

Inductive Effect: Execution in Organic Chemistry

This article details what is Inductive Effect and its Execution in Organic Chemistry. what is Inductive Effect? The covalent bond between the two atoms with dissimilar electronegativity, electron pair forming the bond is never shared absolutely equally. But is attracted a little more towards the more electronegative atom. Such a covalent bond is known as […]

DDQ: Dehydrogenation and Cyclization

DDQ (2 3-dichloro-5 6-dicyano-1 4-benzoquinone) is highly electron-deficient and readily performs dehydrogenation and cyclization. Also used to bring aromaticity in natural products and insertion of the carbonyl group. The substrate must have allylic and benzylic hydrogens to perform dehydrogenation by DDQ. One equivalent DDQ produces one double bond. Different important applications of DDQ are as […]

Aluminum isopropoxide (Oppenauer Oxidation)

Oppenauer oxidation uses metal alkoxides (aluminum isopropoxide) for the oxidation of primary and secondary alcohols with ketones. Ketones act as hydrogen acceptors. This method used in the synthesis of natural products. The reaction conditions are mild, most functional groups are tolerated (alkenes, alkynes, esters, amides, etc.) Isomerization of double bond in oppenauer oxidation, to get […]

Homotopic Enantiotopic Diastereotopic Protons

Based on symmetry criteria protons are classified into three types using NMR splitting. They are homotopic, enantiotopic and diastereotopic protons. This article details the minute characteristic difference between each type of proton. Homotopic protons Symmetry: Protons interchangeable with Cn Symmetry NMR: both protons are chemically equivalent Replacement: protons attached carbon should be achiral before and […]

Manganese dioxide(MnO2) Reagent Selectivity

Manganese dioxide(MnO2) oxidizing Reagent shows excellent Selectivity towards allylic and benzylic alcohols over other alcoholic functions. MnO2 is not affecting olefinic and acetylenic bonds. The reason reaction takes place under mild neutral conditions is an advantage to this reagent. Saturated alcohols are not oxidized by MnO2 under ordinary conditions. Hence MnO2 shows excellent Selectivity towards […]

Birch Reduction Regioselective

Regioselective Birch Reduction of aromatic rings by alkali metals (Li, Na,) in liquid ammonia with ethanol as a proton donor. The regioselectivity of the Birch reduction depends on the nature of the substituent of an aromatic ring. The basic Birch aromatic ring reduction is as follows: This method can reduce aromatic rings, heterocycles, conjugated alkenes, […]

Barton Reaction in Photochemistry

The basic functional group transformation in Barton Reaction in Photochemistry is as follows. Alkyl nitrate ester under thermal or photolytic conditions produces bifunctional γ-hydroxy oximes through oxygen radicals. RULE At least two hydrogens at δ-position to alcohols converted into an γ-hydroxy oximes If at δ-position to alcohols only one hydrogen present barton reaction gives hydroxy […]

Baker-Venkataraman rearrangement

The base-catalyzed rearrangement of ortho-acyloxyketones to beta diketones. This is known as the Baker-Venkataraman rearrangement. β-diketones very important intermediate in the synthesis of chromones, flavones, isoflavones, and coumarins. The basic functional group transformation involved in this reaction include: Bases: KOH, potassium t-butoxide/DMSO, Na/toluene etc Mechanism of Baker-Venkataraman rearrangement Step 1: base abstraction of a proton […]