ch 16

• What type of bonds are reduced to make straight hair curly?

  Disulfide bonds
• What is the purpose of applying an oxidizing agent to hair after curling?

  To re-form disulfide bonds for curls
• What are the two broad classes of compounds containing a carbonyl group?

  1. Compounds with only C and H atoms

  • Aldehydes: at least one H atom
  • Ketones: two alkyl groups

  1. Compounds with an electronegative atom (N, O)
• What is the geometry of the carbonyl atom?

  Trigonal planar with 120° bond angles
• Why is the carbonyl group considered polar?

  O is more electronegative than C
• How does the electron density differ in the carbonyl group?

  The carbonyl C is e- rich, O is e- poor
• What is the IUPAC naming process for aldehydes?

  1. Find the longest chain with CHO
  2. Change “-e” to “-al”
  3. Number the chain to put CHO at C1
  4. Apply other nomenclature rules
• What suffix is used in common names for aldehydes?


  • aldehyde
• What is the IUPAC naming process for ketones?

  1. Find the longest chain with carbonyl
  2. Change “-e” to “-one”
  3. Number the chain for lower carbonyl number
  4. Apply other nomenclature rules
• What is the common naming convention for ketones?

  Name both alkyl groups alphabetically, add “-ketone”
• Why do aldehydes and ketones have higher boiling points than hydrocarbons?

  They are polar molecules with stronger forces
• Why do aldehydes and ketones have lower boiling points than alcohols?

  They lack O-H bonds for hydrogen bonding
• In which solvents are aldehydes and ketones soluble?

  Organic solvents
• What is the solubility of aldehydes and ketones with 6 C's or less in water?

  They are soluble in water
• What happens to aldehydes and ketones with 7 C's or more in terms of water solubility?

  They are insoluble in water
• What is the simplest aldehyde?

  Formaldehyde (CH2=O)
• What is formaldehyde used for?

  Starting material for resins and plastics
• What is the simplest ketone?

  Acetone [(CH3)2C=O]
• What is acetone commonly used for?

  Industrial solvent and starting material
• What unusual condition is associated with high levels of acetone?

  Found in diabetic patients
• What is cinnamaldehyde derived from?

  Cinnamon bark
• What is vanillin primarily extracted from?

  Vanilla bean
• What is citral known for?

  Characteristic odor of lemon grass
• What is citronellal used for?

  To repel mosquitoes
• What are the two general types of reactions aldehydes and ketones undergo?

  1. Aldehydes can be oxidized to carboxylic acids
  2. Aldehydes and ketones undergo addition reactions
• Why can't ketones be oxidized?

  They lack a C-H bond
• What reagent is used to selectively oxidize aldehydes?

  Tollen's reagent
• What does reduction result in for aldehydes and ketones?

  • Decrease in C—O bonds
  • Increase in C—H bonds
• What do aldehydes reduce to?

  1° alcohols
• What do ketones reduce to?

  2° alcohols
• What is a common reagent used for the reduction of aldehydes?

  H2 gas with Pd metal
• How do biological systems reduce carbonyl compounds?

  • Use coenzyme NADH with an enzyme
  • NADH is oxidized to NAD+
• What is the chemistry of vision in rod cells centered around?

  • The aldehyde 11-cis-retinal
  • Isomerization occurs when light hits the retina
• What happens to 11-cis-retinal when light hits the retina?

  It is isomerized to trans double bond
• What must happen to all-trans-retinal for the vision process to continue?

  It must convert back to 11-cis-retinal
• What is the process to convert all-trans-retinal back to 11-cis-retinal?

  • Series of biological oxidation and reduction reactions
  • Involves reduction by NADH to all-trans-retinol
• What happens to all-trans-retinol after it is formed?

  It is isomerized to 11-cis-retinol
• What is the final step in converting 11-cis-retinol back to 11-cis-retinal?

  Oxidized by NAD+
• What can a lack of Vitamin A in the diet cause?

  Night blindness
• What do aldehydes undergo when reacting with alcohols?

  • Form hemiacetals and acetals
  • Requires H2SO4 for acetal formation