Ch 20 - Carboxylic Acids

Ch 20 - Carboxylic Acids - 20 C a rboxyl ic Aci d s The...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
20 Carboxylic AcIds The combination of a carbonyl group and a hydrOxYl on the same carbon atom is caLLed a caRboxYL group. Compounds containing the caRboXyL group are distinct±y acidic and aRe ca²±ed carboxYLic acids± o Ii - C - ³ - H carboxyl g roup o II ´ µ C - ³ - H caRbOxylic acid ´µ C³³ H ´¶ C0 2 H cOndensed stRuctuRes CarboXy±ic acids aRe cLassiFed accoRding to the substituent bonded to the carboXyL gRoup. An aLiphatic acid has an a±ky± gRoup bonded to the carboXy± group, and an aro- maTIc acid has an aRyL group. The simpLest acid is formIc acId, with a pRoton bonded to the caRboXy± group. FattY acIds are Long·chain a±iphatic acids derived from the hydRo²y¸ sis of fats and oi±s (Section ¹º»6). o H- C µ ³ µ H fORmic acid o II CH 3 ¼C½ ¾ - C µ 0 µ H p±OpiOnic acId (aN aLiphatic acid) o < O ) -³µ H benzOic acid (an aROmatic acid) A carboXyLic acid donates p¿otons by heteroLytic cLeavage of the acidic 0µH bond to give a proton and a carboxYLate ioN² We consider the ranges of acidity and the factors aÀÁecting the acidity of carboXyLic acids in Section ¹º·4 o ii ´- C µ ³ - H + caRbOxyl²c acid 20-2A Common Names o ±± Hz³ (- ´ µ C µ ³ à caRbOxylate iOn + ½³Ä 3 SeveRaÅ aLiphatic carboXyLic acids have been known for hundreds of years, and their common names refLect theiR historica± souRces. FormIc acId was eXtRacted from ants: formIcA in Æatin. Acetic acid was isoLated from vinegaR, caLLed acetuM ("souRÇÈ in Æatin Propionic acid was considered to be the ÉIrst fatty acidÊ and the name is derived fRom the Greek pRtoS pIon (ËÌrst fatÍÈ. ButyRic acid resu²ts from the oXidation of butyraLdehyde, 20-1 Introduction steaRic acid (a Fatty acid) 20-2 Nomenclature of Carb oxylic Acids 935
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon