HYDROLYSIS REACTIONS hydrolysis of esters

HYDROLYSIS REACTIONS HYDROLYSIS REACTIONS O CR O R O CR O + OH _ + R O H O CR O R O CR OH + + R O H H 2 O H 2 SO 4 Hydrolysis of Esters Hydrolysis of Esters Basic Solution Acidic Solution excess heat heat Hydrolysis requires strong acid or base and heating under re#ux. … It’s not easy ! Na + Na + : _ : O CR O R' H O : : O CR O R' OH _ : slow : : O CR O R' OH _ : : : O CR O R' O H _ : : : O CR O R' OH _ : : : O CR OH : O R' : + R C O O : _ O R'H + _ Hydrolysis of an Ester in Base Hydrolysis of an Ester in Base proton transfers H-OH HO - NaOH : O CR O R' H H O H : O CR O R' OH H H slow O CR O R' OH H H O CR O R' O H H H O CR O R' O H H H : + : O CR O R' O H H H : + : O CR OH H : O R' H : + + + : : : + + + : O CR O H Hydrolysis of an Ester in Acid Hydrolysis of an Ester in Acid proton transfers H 3 O + + H 3 O + H-OH 2 + OH 2 H 2 SO 4 / H 2 O O CR NH 2 O CR O + OH _ + O CR NH 2 O CR OH + + H 2 O H 2 SO 4 NH 3 (NH 4 )SO 4 Hydrolysis of Amides Hydrolysis of Amides Basic Solution Acidic Solution excess heat heat Hydrolysis requires strong acid or base and heating under re#ux. … It’s not easy ! Na + Na + : : : _ O CR NH 2 O H : : _ : R C NH 2 O O H : : _ : R C NH 2 O O H : : : + NH 2 : _ O CR O H O CR OH : : + NH 2 : _ O CR O : : : _ + NH 3 Base-Promoted Hydrolysis of a Amide Base-Promoted Hydrolysis of a Amide MECHANISM stronger base than OH - , but this step doesn’t reverse because of the next one once in a while most often this step reverses because OH - is a better leaving group than NH 2 - accumulates NaOH ACYLATION OF ENAMINES ACYLATION OF ENAMINES 1) + R C Cl O RCH C R N CH C R N C R R O + 2) + CH C R N C R R O + R C O CH C R R O + N H H 3 O+ Acylation of an Enamine Acylation of an Enamine acyl group was added Cl - : : O C R Cl C C R R R N : NC R CR R C O R Cl NC R CR R C O R + + : : _ : : + Cl Acylation of an Enamine Acylation of an Enamine Mechanism Mechanism … continued slow enamine iminium salt N H R CH R C O R NCCCR O R R R O H H + NCCCR O R R R O H H : : : : : + Acylation of an Enamine Acylation of an Enamine Mechanism (cont) Mechanism (cont) NCCCR O R R R O H H : : : + NH : : CCCR O R R R O : O H H H O HH + [...]...SUMMARY OF ACYLATION H O HOTs R C C R + N R R :N C C R R H + H2O enamine + N O :N C C R R + O R R C Cl R C C C R R R acyl group O R N R C C C R R + H3O+ O R O R C C C R R + N H MISCELLANEOUS REACTIONS OF ACID DERIVATIVES Reaction of Esters with Organometallic Reagents O 1) ether R C O R" + 2 R' MgBr 2) H2O, acid OH R C R' + MgBr (OR") + MgBr(OH) R' cleaves the ether … reacts twice ! Reduction of Esters. .. R C O + 2 LiAlH4 R' 4 R CH2 OH + 2 LiOH + + 4 R' OH 2 Al(OH)3 Reduction of Esters to Aldehydes O R C O R' DIBALH H2O toluene -78°C HCl O R C H + R' OH NITRILES REACTIONS AND SYNTHESIS Formation of Nitriles SN2 Reaction _ R CH2 Cl + : C N : R CH2 C N + Cl Addition to C=O +O H O H R C R :C N pH 6 R C R C N cyanohydrin Hydrolysis of Nitriles ACID SOLUTION H2SO4 R CH2 C N + H2O BASIC SOLUTION heat O R... Base-Promoted Hydrolysis of a Nitrile MECHANISM R C N 1) 2) 3) slow _ :O H : N: NaOH _ R C N: :O H _ R C OH : NH + H2O : NH R C OH : NH2 R C OH R C O _ + OH amide Tautomerism … continued Base-Promoted Hydrolysis of a Amide MECHANISM : O: 4) R C NH2 :O H _ :O H 5) _ :O : R C NH2 : O: R C : O: 6) _ + : NH2 :O H :O H R C OH NaOH _ :O: R C NH2 _ + : NH2 : O: _ R C O: + NH3 Acid-catalyzed Hydrolysis of a Nitrile... Nitrile MECHANISM + H 1) R C N 2) + + R C N H slow R C N H + :O H O H H 3) H2SO4 / H2O H R C N H :O H + H + R C N H + R C N H fast H-OH2 + R C N H + : O: H H protonated amide … continued Acid-catalyzed Hydrolysis of a Amide + :O H 4) :O H R C NH2 R C NH2 + :O H O H H :O H 5) R C NH2 + :O H H 6) :O H + R C NH3 + H-OH2 H OH2 :O H + R C NH2 H H + :O H R C NH2 :O H :O H + :O H R C OH + :NH3 :O H O R C OH + . HYDROLYSIS REACTIONS HYDROLYSIS REACTIONS O CR O R O CR O + OH _ + R O H O CR O R O CR OH + + R O H H 2 O H 2 SO 4 Hydrolysis of Esters Hydrolysis of. Base-Promoted Hydrolysis of a Amide Base-Promoted Hydrolysis of a Amide MECHANISM stronger base than OH - , but this step doesn’t reverse because of the