Hydrocarbon Derivatives Aldehydes Ketones Carboxylic Acids Esters Carbonyl

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

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

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

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

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

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

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

Naming Ketones one • always have number (except if 3 C’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 = O CH 3 CH 2 CCH 3 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 • general formula: = O R C OH • identify by –COOH ending • contains: – carbonyl group AND hydroxyl group bonded to same C acidic H+1

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

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

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

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

Naming Carboxylic Acids • name 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

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

CH 3 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 = 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 – due to carbonyl group & O bridge • no H-bonding – no FON • form as product of chemical reaction between organic acid an alcohol • responsible for many distinctive odors

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

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