-higher bps than other organic compounds of comparable MW

*polar compounds and form very strong intermolecular H bonds

-more soluble in H2O than alcohols, ethers, aldehydes, and ketones of comparable MW

*form H bonds w/ H2O molecules through both their C=O and OH groups

*H2O solubility decreases as relative size of hydrophobic portion of molecule (R group) increases

-COOHs=weak acids; pKa falls w/in 4-5

-greater acidity of COOH as compared to alcohols is due to resonance stabiliization of carboxylate anion

-e- w/drawing substituents near carboxyl group increase acidity through inductive effect

-form of COOH in aqueous soln depends on pH of soln

*pH<2.0--> carboxylic acid

*pH of soln=pKa of acid--> carboxylic acid and carboxylate anion

*pH>7.0--> carboxylate anion

-COOHs react w/ KOH, NaOH, and other strong Bs to give H2O soluble salts

-Also form H2O soluble salts w/ ammonia and amines

-React w/ sodium bicarbonate and sodium carbonate to form H2O soluble salts and carbonic acid

*carbonic acid then breaks down to CO2 and H2O

-acetic acid synthesized by carbonylation of methanol

-Monsanto process uses soluble rhodium(III) salt and HI to catalyze rxn

-carboxyl group very resistent to reduction

*not affected by catalytic hydrogenation under conditions that easily reduce aldehydes and ketones to alcohols and reduce alkenes/alkynes to alkanes

*not reduced by NaBH4

-LiAlH4 reduces carboxyl to 1' alcohol

*reduction carried out in diethyl ether, THF or other nonreactive aprotic solvent

-esters can be prepared by treating COOH w/ an alcohol in presence of an acid catalyst , commonly H2SO4, ArSO3H, or gaseous HCl

-alcohol can be used in excess to drive equilibrium to right

*or H2O can be removed by azeotropic distillation and Dean stark trap

-key intermediate is TCAI formed by addition of ROH to C=O group

 -treating COOH w/ diazomethane gives methyl ester

-esterification in 2 steps:

1. proton transfer to diazomethane

2. nucleophilic displacement of N2

-functional group is C=O group bonded to halogen atom

*acid chlorides=most common and most widely used

-->acid chlorides most often prepared by treating carboxylic acid w/ thionyl chloride; 2 steps:

1. rxn w/ SOCl2 transforms OH (poor LG) into chlorosulfite group (good LG)

2. attack of chloride ion gives TCAI, which collapses to give acid chloride

-loss of CO2 from carboxyl group

-most COOHs if heated very high undergo thermal decarboxylation

*however most are pretty resistant to moderate heat and melt/boil w/o decarboxylation

*exceptions=COOHs that have C=O beta to carboxyl group; this type undergoes decarboxylation on mild heating

-thermal decarboxylation of beta-ketoacid involves rearrangement of 6 e-s in cyclic 6-membered transition state

-decarboxylation occurs if there's any C=O group beta to carboxyl