Question

Write the application of Grignard reagent.

Hint:

Grignard reagents are powerful nucleophiles that add to carbonyl compounds to build carbon–carbon bonds. Always prepare them under anhydrous conditions since they react violently with water.

Answer 1

Grignard reagents (RMgX, where R = alkyl/aryl, X = halogen) are highly reactive organometallic compounds used widely in organic synthesis.
Applications:
1. Synthesis of alcohols:
\[ \mathrm{R{-}MgX + CH_2O \;\longrightarrow\; RCH_2OMgX \xrightarrow{H_2O} RCH_2OH} \] (Formation of primary alcohol).
\[ \mathrm{R{-}MgX + R'CHO \;\longrightarrow\; RCH(OH)R'} \] (Formation of secondary alcohol).
\[ \mathrm{R{-}MgX + R'COR'' \;\longrightarrow\; R_3COH} \] (Formation of tertiary alcohol).
2. Formation of hydrocarbons:
\[ \mathrm{R{-}MgX + H_2O \;\longrightarrow\; RH + Mg(OH)X} \] 3. Synthesis of carboxylic acids:
\[ \mathrm{R{-}MgX + CO_2 \;\longrightarrow\; RCOOMgX \xrightarrow{H_2O} RCOOH} \] Thus, Grignard reagents are versatile tools for forming C–C bonds and synthesising alcohols, hydrocarbons, and carboxylic acids.