Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Chapter 16 Functional Group Aldehydes Carbonyl (-C=O) Contains a polar bond RCHO Aliphatic chains NOT as part of ... Aliphatic rings or Aromatic rings Nomenclature Aldehydes IUPAC Alkanal Carbonyl C = #1 Common Prefixaldehyde ALDEHYDES & KETONES Ketones Carbonyl (-C=O) Contains a polar bond RCOR Aliphatic chains Aliphatic rings NOT as part of Aromatic rings Ketones Alkanone Carbonyl C = lowest # possible Propanone = acetone Alkyl alkyl ketone Multi-functional Group Compounds To determine which suffix to use, follow this priority list (high to low): Substituent name Aldehyde Ketone oxoAlcohol hydroxyAlkene en- (before suffix) Alkyne yn- (before suffix) Alkoxy alkoxyAlkyl alkylHalogen haloIsomerism Aldehydes Constitutional Skeletal Ketones Skeletal Positional Common & Naturally Occurring Aldehydes & Ketones Aldehydes Ketones Formaldehyde Acetone Acetaldehyde Odors/Flavors Odors/Flavors Cloves (2-heptanone) Vanillin Butter (butanedione) Benzaldehyde Fresh-mown hay (coumarin) Cinnamaldehyde Steroid Hormones Testosterone Progesterone Cortisone Physical Properties Aldehydes Ketones Boiling Point Alkanes<Aldehydes<Alcohols Same as for Aldehydes Bonding/polarity Water Solubility Water can H-bond with aldehydes Mass relationship Same as for Aldehydes Acetone is infinitely soluble* Odors Low MW = unpleasant High MW = fragrant Preparation Reactions Aldehydes Oxidation 1˚ alcohol --> aldehyde Pleasant Perfumes & air fresheners Ketones 2˚ alcohol --> ketone Chemical Reactions - Oxidation Aldehydes Aldehyde --> Carboxylic acid Ketones Ketone --> NR Chemical Reactions - Tollen’s Reagent Aldehydes RCHO + Ag+ -->RCOOH + Ag(s) Ketones RCOR + Ag+ --> NR Chemical Reactions - Fehling’s or Benedict’s Reagent Aldehydes Ketones RCHO + Cu2+ --> RCOOH + Cu2O RCOR + Cu2+ --> NR Diabetes test Chemical Reactions – Reduction (Opposite of Oxidation) Aldehydes Ketones RCHO --> 1˚ alcohol RCOR --> 2˚ alcohol Chemical Reactions - Reaction with Alcohol Aldehydes Ketones RCHO + ROH --> Hemiacetal RCOR + ROH --> Hemiacetal (unstable, unless cyclic) Hemiacetal + ROH --> Acetal Hemiacetal + ROH --> Acetal Hydrolysis of acetal produces the aldehyde + 2 alcohol molecules CH2(OCH3)2 --> HCHO + 2CH3OH Hydrolysis of acetal produces the ketone + 2 alcohol molecules Phenol + Formaldehyde: Phenols and formaldehyde react via substitution reactions and polymerize via dehydration reactions. Plastics and adhesives (for plywood) DMSO (dimethyl sulfoxide): sulfur analog of Acetone Penetrates skin very quickly. Anti-inflammatory rub Reduces to dimethyl sulfide in the body. Garlic-like odor What do you need to know? Structural characteristics (know the functional group) Aldehydes Ketones Acetals Isomers Nomenclature (the rules for naming the molecules) Common & IUPAC Physical properties (basic/simple) BP; Solubility; Flammability Occurrence and uses (common) Natural (ex.: nuts & spices,melted butter odor, melanin ) Synthetic (ex.: formalin, Bakelite) Preparation (what basic reactions produce the molecules) Aldehydes - oxidation of 1˚ alcohols Ketones - oxidation of 2˚ alcohols Characteristic reactions of the molecules Oxidation-reduction Fehling’s & Tollens’ reactions rxn w/ alcohols