Hydrocarbon Derivatives Aldehydes Ketones Carboxylic Acids Esters

Carbonyl Group functional group: -C  O I results in strong dipole-dipole forces aldehydes contribute to odors such as: –rosemary, daffodil, bitter orange, camphor, angelica, fennel, mustard, & peppermint

Al Aldehydes general formula: R  C  H or R-CHO Naming: find name of alkane with same # of C’s al drop the –e in –ane add –al never need #’s for aldehyde names always –carbonyl group always on end C  O

H  C  H H = O OH  H  C  H + H 2 aldehydes created by dehydrogenating alcohols

HCHHCH  O methanal H H  C  C  H H  O ethanal common name = formaldehyde common name = acetaldehyde carcinogenic compound component of cigarette smoke natural component of many over-ripe fruits

CH 3 CH 2 CH 2 CHO CHO ending indicates aldehyde 4 carbons so base name is butane drop -e and add al  butanal

Properties of Aldehydes C=O R H   R H   ++++ ---- -- ++++ aldehydes are polar! ↑ bp over alkane with same C’s H-bonding with H 2 O which ↑ solubility in water H O ++ --

Ketones carbonyl group: -C=O I on – located on C in middle of chain not end C general format: R and R‘: may or may not have same # C’S R  C  R' = O

one Naming Ketones always have number (except if 3C’s) take alkane name: drop -e (from ane ending) & add –one use # to show location of functional group: # chain so >C=O on lowest C

H O H H  C  C  C  H H H = propanone common name = acetone CH 3 CH 2 CH 2 CCH 3 = O 2-pentanone

Properties of Aldehydes & Ketones aldehydes & ketones: –contain C=O group polar (soluble in water) boiling point: –higher than alkanes (same # C’s) –lower than alcohols (same # C’s) known for appealing tastes & smells –flavorings in food & candy –fragrances in perfumes –examples: vanilla & cinnamon

Carboxylic Acids Hgeneral formula: R  C  OH identify by –COOH ending contains: –carbonyl group AND hydroxyl group bonded to same C = O acidic H +1

dissociation of acetic acid H 2 O(l) CH 3 COOH(l)  CH 3 COO -1 (aq)+ H +1 (aq) Remember all acids dissociate in water! - carboxylic acids are electrolytes!

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

Which of the following is an electrolyte? A.CH 3 OH B.CH 3 COOH C.CH 2 O D.C 3 H 6 O correct answer is B (carboxylic acid) alcohol aldehyde ketone

Which of the following is a non-electrolyte? A.HCl B.CH 3 COOH C.NaOH D.CH 3 OH correct answer is D (alcohol)

Naming Carboxylic Acids name nevername never needs number: –functional group always on end C find name alkane: drop –e from -ane ending & add -oic + acid common carboxylic acids: acetic acid – vinegar – produced in doughs leavened with specific yeast (ex: sourdough bread) lactic acid –produced in overworked muscles & causes pain –poly(lactic acid) – biodegradable polymers used as surgical sutures

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

CH 3 CH 2 CH 2 CH 2 COOH 5 C ’ s  pentane so the name is pentanoic acid

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 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 = O

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

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

Naming Esters name hydrocarbon branch bonded to O bridge first add prefix –yl base name derived from branch containing carbonyl group - base name: drop the -e from -ane ending & add –oate - don’t forget to count the C in the carbonyl group

CH 3 CH 2 CH 2 C  O  CH 2 CH 3 = O name this branch 1 st ethyl butanoate bridge O pineapple

CH 3 C  O  CH 2 CH 2 CH 2 CH 2 CH 3 = O bridge O name this branch 1 st pentyl ethanoate banana

CH 3  O  C  CH 2  CH 2  CH 3 = O bridge O name this branch 1 st methyl butanoate apple

CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -O-C-CH 3 O = bridge O name this branch 1 st octyl ethanoate orange