Question

Chem 202, Fall 2019 Homework Packet 9 (Carboxylic Acid Derivatives) 2. Reactivity of Carboxylic Acid Derivatives a. Rank the following carboxylic acid derivatives in order from LEAST reactive to MOST reactive when they undergo nucleophilic acyl substitution reactions: — '— ' la do lan loons obe OCH3 b. Justify your answer thoroughly in words. Your explanation should include, if applicable, definitions and explanations that cover leaving group ability, conjugate acid strengths, pKa values, etc. 4. Amide Formation Mechanism: Draw the proper FULL electron-pushing mechanism for the reaction below to synthesize Lidocaine, including ALL intermediates (with formal charges) and electron pushing arrows. Label the Electrophile and Nucleophile in each step! Use the synthesis of DEET in your notes to help you, it's the same mechanism din cele - dr. Leo

Answer 1

Reactivty op Canboxyic acideniyatiyes C A OCH3 NH A (b). The genenal onde oe neactivity Of acsa deivatives Con be explaíned by talking Tnto a ccount the ba stcity op the le@ning 9roups a cyl chlondes eact the leaving When 9roup fs a chloni ede lon o anhydnide , the teauing 91op canbow latefon e ste the Teaying goop alkoxide fon the leaving 9oop amine anfon amtde In Canbonglic ia the leavimg gP tydoide Ton base 900p leakest moie eactive elimtnatfon MCchan?sm adadttion G weak base Mone G eliminatfon reactive 1n

ae basee these pka values op The consugate base Conjugate Aud Pka - 7 4.TS Ch cooH 16 Ct-OH NH2 NH3 38 15 5 having tgh pka Confugate -Aud Velue then de caease the leavng 9sou nature Nits H weakest tigh Value then Pka leavng groop Strongest leaving g up leaving areup onden NH 2. Nudeophrlte center cl Electephilic Center

Nth HH OH N Deprotiation by base MH N