Question

what is hell volhard zelinsky reaction​

Answer 1

For this reaction alpha hydrogen must be present in acid.

This reaction involves substitution of alpha hydrogen by halogens.

Reagent is bromine in presence of red P and heat

Example is in the attachment

Hope this helps you ☺️

Answer 2

$\huge\underline\mathfrak\red{Question}$

ωнαт ıs нєłł ѵσłнαя∂ zєłıηsky яєαcтıση

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$\huge\underline\mathfrak\blue{Answer}$

The Hell-Volhard-Zelinsky reaction is an organic reaction used to convert a carboxylic acid with an α-hydrogen and a halogen, to an α-halo carboxylic acid, using a $\red{ phosphorous \ catalyst \ and \ water. }$ The mechanism begins with the reaction of the carbonyl oxygen with phosphorous trihalide to form a P–O bond and release a halide anion. The halide then attacks the carbonyl to form an intermediate which rearranges to release an acyl chloride, an acid molecule, and a phosphine oxide. The acyl chloride then tautomerizes to the enol form which subsequently attacks the halogen molecule to form an α-halo acyl halide. Water hydrolysis yields the final α-halo carboxylic acid product.

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$\huge\green{Note :}$ Ask your Question properly with explanation.

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Hope it helps :))