Organic I - addition of alternate nucleophiles to carbonyls

NO MECHANISMS JUST CONDITIONS AND EXPLANATIONS

What classification are Grignard and organolithium reagents?

Organometallic reagents

What are the two types of Grignard reagent?

• R—MgBr

• R—MgCl

How is the R—metal bond polarised?

• R group is delta -

• Metal is delta +

• Metal is more electropositive than carbon

How do you prepare Grignard reagents?

• Reagents: R—Br/Cl and Mg

• Solvent: dry solvent (Et2O)

How do you prepare organolithium compounds?

• Reagents: R—Br and 2Li

• Solvent: dry petrol (hexane/toluene)

What does reaction of aldehydes and ketones with Grignard/organolithium form?

• Aldehydes form secondary alcohols

• Ketones form tertiary alcohols

What does adding water to aldehydes/ketones form?

Aldehyde/ketone hydrates

How does changing substituents change the production of hydrates?

• Increasing substituent size on C=O makes hydrate formation less favourable

• Decreases equilibrium constant value with increased sterics

How does adding withdrawing groups to a molecule change hydrate formation?

• -I inductive effect makes the carbon of C=O more delta+ - more reactive

• Hydrates are more readily formed