CHEM 203 Lecture Notes - Lecture 28: Wurtz Reaction, Sn2 Reaction, Nucleophilic Addition
Document Summary
Similar (but not identical) reactivity of organo-li compounds and of grignard reagents. Organo-na and k compounds as highly ionic species that react very rapidly with alkyl halides, via sn2 reactions, leading to the formation of alkanes; e. g. ch3 br + 2 na ch3 na ( + nabr) In the above process, the rate of formation of ch3na is slower than the rate of the sn2 reaction of ch3na with ch3br leading to ethane. Thus, the organometallic compound does not survive the conditions of its formation. The overall process is termed a wurtz reaction, and it is no longer a useful transformation. Nucleophilic addition of grignard or lithium reagents to aldehydes and ketones: reaction of a grignard (or organo-li) reagent with generic aldehydes: formation of secondary alcohols; e. g. ch3 mgbr ch3. C oh a secondary alcohol reaction of a grignard (or organo-li) reagent with formaldehyde: formation of primary alcohols; e. g. ch3 ch2-mgbr ch3 ch2 mgbr formaldehyde.