Hydrocarbon Derivatives Aldehydes Ketones Carboxylic Acids Esters

Carbonyl Group >CO oxygen attached to carbon by double covalent bond strong dipole-dipole forces

Aldehydes O general formula: RCH or RCHO carbonyl group always at end of aldehyde find name of alkane with same # of C’s drop the -e (in ane ending) to –al never need #’s for aldehydes functional group always on end C 

O OH = HCH H  HCH + H2 aldehydes created by dehydrogenating an alcohol

O HCH methanal  O ethanal H HCCH  common name = formaldehyde common name = acetaldehyde

Acetaldehyde carcinogenic compound component of cigarette smoke natural component of many over-ripe fruits contributes to odors such as: rosemary, daffodil, bitter orange, camphor, angelica, fennel, mustard, & peppermint

CH3CH2CH2CHO CHO ending indicates aldehyde 4 carbons so base name is butane drop -e and add al  butanal

Properties of Aldehydes - O R H H R - -  +  C=O C=O   + + H H aldehydes are polar! ↑ bp over alkane with same C’s H-bonding with H2O which ↑ solubility in water

Ketones O = RCR' carbonyl group: >C=O located on C in middle of chain instead of at end general format: R and R‘: represent hydrocarbon chain - may or may not be the same O = RCR'

Naming Ketones nearly always have number (except 3C’s) take corresponding alkane name: drop -e (from ane ending) & add -one # gives location of functional group: >C=O (lowest possible #)

H O H HCCCH H H propanone O = CH3CH2CH2CCH3 2-pentanone = common name = acetone O = CH3CH2CH2CCH3 2-pentanone

Aldehydes & Ketones known for appealing tastes & smells flavorings in food & candy fragrances in perfumes examples: vanilla & cinnamon

Properties of Aldehydes & Ketones contain C=O group polar (soluble in water) boiling point: higher than alkanes (same # C’s) lower than alcohols (same # C’s)

Carboxylic Acids O acidic H+1 general formula: RCOH contains: = carbonyl group AND hydroxyl group bonded to same C =

dissociation of acetic acid Remember all acids dissociate in water! - carboxylic acids are electrolytes! CH3COOH(l) + H2O(l)  CH3COO-1(aq)+ H+1(aq)

Carboxylic Acids = general format: R-C-OH or R-COOH O

Which of the following is an electrolyte? alcohol CH3OH CH3COOH CH2O C3H6O aldehyde ketone correct answer is B (carboxylic acid)

Which of the following is a non-electrolyte? HCl CH3COOH NaOH CH3OH correct answer is D (alcohol)

Naming Carboxylic Acids never needs number: functional group always at end find name corresponding hydrocarbon drop -e (from ane ending) & add -oic + acid

O = HCOH 1 C  methane methanoic acid sting from red ants, bees O H HCCOH = ethanoic acid acetic acid 2 C  ethane

CH3CH2CH2CH2COOH 5 C’s  pentane so the name is pentanoic acid

Common carboxylic acids acetic acid – vinegar produced in doughs leavened with specific yeast (ex: sourdough bread) citric acid tannic acid ascorbic acid lactic acid produced in overworked muscles & causes pain poly(lactic acid) – biodegradable polymers used as sutures in internal surgery

Properties of Carboxylic Acids contain -COOH group H bonded to O therefore hydrogen bonding bp ↑ over corresponding alkane form H bonds with water so smaller acids are very soluble in water

Esters O = general format: RCOR‘ R and R‘ = hydrocarbon branches can be same or different esters contain carbonyl group and an O bridge both in middle of chain

Esters esters are POLAR no H-bonding due to carbonyl group & O bridge no H-bonding no FON form as product of chemical reaction between organic acid and an alcohol

Esters O = RCOR‘ or RCOOR’ reaction between carboxylic acid & alcohol: carbonyl group & “R” come from carboxylic acid bridging O & R’ come from alcohol

Esters responsible for many distinctive odors pineapple banana orange wintergreen

Naming Esters name hydrocarbon branch bonded to O bridge first prefix –yl base name derived from branch containing carbonyl group count up all C’s in this branch including the C in the carbonyl hydrocarbon base name drop the -e (from ane ending) & add -oate

name this branch 1st O = CH3CH2C─O─CH3 carbonyl group bridge O methyl propanoate

bridge O O = CH3CH2CH2COCH2CH3 name this branch 1st ethyl butanoate pineapple

bridge O O = CH3COCH2CH2CH2CH2CH3 name this branch 1st pentyl ethanoate banana

O = CH3OCCH2CH2CH3 bridge O name this branch 1st methyl butanoate apple

CH3CH2CH2CH2CH2CH2CH2CH2-O-C-CH3 = CH3CH2CH2CH2CH2CH2CH2CH2-O-C-CH3 bridge O name this branch 1st octyl ethanoate orange