Reaction with Carbonyl R:attacks the partially positive carbon in the carbonyl. The intermediate is an alkoxide ion. Addition of water or dilute acid protonates the alkoxide to produce an alcohol. OH
Reaction with Carbonyl ❖R:- attacks the partially positive carbon in the carbonyl. ❖The intermediate is an alkoxide ion. ❖Addition of water or dilute acid protonates the alkoxide to produce an alcohol. R C O R C O HOH R C OH OH
Grignard and Ester Grignard attacks the carbonyl. Alkoxide ion leaves！？I HgC CH3 R-MgBr C-0: R-C-690 MgBr CH3O OCH3 CH3 CH3 O⊕ R-C708 MgBr R-C=o. MgBrOCH3 focHa Ketone intermediate
Grignard and Ester ❖Grignard attacks the carbonyl. ❖Alkoxide ion leaves! ? ! C O CH3O H3C R MgBr C MgBr CH3 OCH3 R O C CH3 OCH3 R O MgBr C CH3 R O + MgBrOCH3 Ketone intermediate
Second step of reaction Second mole of Grignard reacts with the ketone intermediate to form an alkoxide ion. Alkoxide ion is protonated with dilute acid, CH3 CH3 R-MaBr R-C R-C-699 MgBr R HOH CH3 R- C-OH R
Second step of reaction ❖Second mole of Grignard reacts with the ketone intermediate to form an alkoxide ion. ❖Alkoxide ion is protonated with dilute acid. C CH3 R O R MgBr + C CH3 R R O MgBr HOH C CH3 R R OH
How would you synthesize... OH CH3 OH CH3CH2CCH3 CH3CH2CHCH2CH3 CH3 OH CH2OH OH CH3CH2CHCH2CH2CH3 OH OH C-CH3 CH3 CH2CH3
How would you synthesize... CH3CH2CCH3 OH CH3 C OH CH3 CH3CH2CHCH2CH3 OH CH3CH2CHCH2CH2CH3 OH CH2OH OH CH3 C OH CH2CH3 CH3
Grignard Acid Chloride(1) Grignard attacks the carbonyl. Chloride ion leaves. HgC CH3 R-MgBr C-0: R-CMgBr CI CHg CHg R-C MgBr R-C-O MgBrCl Ketone intermediate
Grignard + Acid Chloride (1) C O Cl H3C R MgBr C MgBr CH3 Cl R O C CH3 Cl R O MgBr C CH3 R O + MgBrCl Ketone intermediate ❖Grignard attacks the carbonyl. ❖Chloride ion leaves