Grignard addition co reactant

Overview

Aldehydes plus Grignard reagents give secondary alcohols after acidic work-up.

Transformation

Aldehydes → Secondary alcohols

Equation

R'CHO + R-MgX -> R'CH(OMgX)R; then H3O+ -> R'CH(OH)R

Reagents

Grignard reagent, then dilute acid

Environment

dry ether, then acidic work-up

Reaction class

nucleophilic addition

Mechanism

Grignard carbonyl addition

Evidence level

textbook core

Scope and limitations

Scope

Aldehydes other than methanal are carbonyl co-reactants that give secondary alcohols after Grignard addition and acidic work-up.

Limitations

This record represents the aldehyde co-reactant branch of Grignard addition; methanal is represented separately because it gives primary alcohols.

Related reactions

• Cyanohydrin formation: Aldehydes → Hydroxynitriles

  Cyanide addition to an aldehyde forms a hydroxynitrile, giving a carbonyl-route analogue of the nitrile chain-extension motif.

• Oxidation: Alcohols → Aldehydes

  Controlled oxidation of a primary alcohol gives an aldehyde.

• Controlled oxidation: Primary alcohols → Aldehydes

  Controlled oxidation of a primary alcohol gives an aldehyde.

• Oxidation: Secondary alcohols → Ketones

  Oxidation of a secondary alcohol gives a ketone.

• Reduction: Aldehydes → Primary alcohols

  Reduction of an aldehyde gives a primary alcohol.

• Reduction: Ketones → Secondary alcohols

  Reduction of a ketone gives a secondary alcohol.

• Oxidation: Aldehydes → Carboxylic acids

  Oxidation of an aldehyde gives a carboxylic acid.

• Carbonyl addition: Grignard reagents → Secondary alcohols

  Grignard addition to aldehydes gives secondary alcohols after work-up.

References

1. Organic Chemistry: Nucleophilic Addition of Hydride and Grignard ReagentsJohn McMurry · OpenStax Organic Chemistry · 2023

   Supports Grignard carbon nucleophiles adding to aldehydes and ketones to give alkoxide intermediates, followed by protonation during acidic work-up.