1. Topic: Functional Group #5-Aldehydes Do Now: Write the molecular formula for the two sugars on the right. Are they isomers?

2. General formula: R  C  H or RCHO alwaysCarbonyl group just like ketone except always at end of aldehyde –Attached to Carbon chain on one side and a H on the other  O

3. Properties = same as ketones C=O R H   R H   ++++ ---- -- ++++ Aldehydes are polar! Dissolve in water Dipole-Dipole interactions Boiling point: higher than alkanes (same # C’s) lower than alcohols (same # C’s) H O ++ --

4. Acetaldehyde (ethanal) = important aldehyde Occurs naturally in Coffee Bread Ripe fruit Produced by plants Produced by the partial oxidation of ethanol in the liver and may be a contributing factor to hangovers from alcohol consumption It’s an air pollutant resulting from combustion (car exhaust and cigarette smoke)

5. Flavoring agents

6. Naming Find name of alkane with same # of C’s al –change the -e to -al Never need #’s for aldehydes –b/c functional group always on end C

7. HCHHCH  O Methanal H H  C  C  H H  O Ethanal common name = acetaldehyde common name = formaldehyde

8. CH 3 CH 2 CH 2 CHO CHO ending indicates aldehyde 4 Carbons so base name is butane Drop -e and add al  butanal