Carbonyl addition
Grignard addition to aldehydes gives secondary alcohols after work-up.
- Reagents
- aldehyde then dilute acid
- Conditions
- dry ether, then acidic work-up
- Reaction class
- nucleophilic addition
- Equation
- R-MgX + R'CHO -> R'CH(OMgX)R; then H3O+ -> R'CH(OH)R
Overview
Grignard addition to aldehydes gives secondary alcohols after work-up.
Transformation
Grignard reagents → Secondary alcohols
- Equation
- R-MgX + R'CHO -> R'CH(OMgX)R; then H3O+ -> R'CH(OH)R
- Reagents
- aldehyde 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
- Grignard reagents add to aldehydes other than methanal and, after work-up, give secondary alcohols.
- Limitations
- This route records the carbonyl-addition and acidic work-up outcome; methanal gives primary alcohols, other aldehydes give secondary alcohols.
Related reactions
- Oxidation: Secondary alcohols → Ketones
Oxidation of a secondary alcohol gives a ketone.
- Reduction: Ketones → Secondary alcohols
Reduction of a ketone gives a secondary alcohol.
- Grignard formation: Chloroalkanes → Grignard reagents
Chloroalkanes can react with magnesium in dry ether to form Grignard reagents.
- Grignard formation: Bromoalkanes → Grignard reagents
Bromoalkanes can react with magnesium in dry ether to form Grignard reagents.
- Grignard formation: Iodoalkanes → Grignard reagents
Iodoalkanes can react with magnesium in dry ether to form Grignard reagents.
- Carbonyl addition: Grignard reagents → Primary alcohols
Grignard addition to methanal gives primary alcohols after work-up.
- Carbonyl addition: Grignard reagents → Tertiary alcohols
Grignard addition to ketones gives tertiary alcohols after work-up.
- Carboxylation: Grignard reagents → Carboxylic acids
Grignard carboxylation gives carboxylic acids after acidic work-up.
- Grignard addition co reactant: Aldehydes → Secondary alcohols
Aldehydes plus Grignard reagents give secondary alcohols after acidic work-up.
References
- 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.