Chem 31.1 Post Lab 3

Chem 31.1 Post Lab 311 May 2015Experiment 8CARBONYL COMPOUNDS AND CARBOHYDRATES

Aldehydes and Ketones

Synthesis of AldehydesOxidation of 1 Alcohols

Ozonolysis of Alkenes

Synthesis of KetonesOzonolysis of Alkenes

Ketones from Nitriles

Nucleophilic Addition to the Carbonyl CarbonNote: aldehydes are more reactive than ketones, product: 2 alcohol or 3 alcohol

Nucleophilic Addition to the Carbonyl CarbonMechanism:

Reaction with 2,4 DNP

Solid, oily derivative

Iodoform test: methyl ketones

Yellow precipitate

Tollens Test: test for aldehydesSilver mirror

CarbohydratesPolyhydroxy aldehydes or ketonesClassification:Hydrolysis1. Monosaccharides (glucose, fructose, galactose)2. Disaccharides (sucrose, lactose, maltose)3. Polysaccharides (starch, amylose, amylopectin)B. Functional groups1. Aldoses (glucose)2. Ketoses (fructose)C. Number of Carbon atoms1. Hexoses (glucose)2. Pentoses (fructose)

Glucose

fructose

galactose

Glucose + fructose

Glucose + galactose

Glucose + glucoseCarbohydrates

Structural Formulae for Monosaccharides

AnomersDiastereomers which differ only at the hemiacetal or acetal carbon are called anomers. Can be an anomer or anomer depending on the location of the OH group

Polysaccharides

Hemiacetal CarbonThe essential features of a hemiacetal carbon are an OH and an OR group attached to the same carbon atom.

Hemiacetal Carbon

Hemiacetal carbon carbonyl carbon(marked with an asterisk)aldehydeHemiacetal Carbon

ketoneCarbohydrates are reactive only if it is in the open chain structureHydrolysis of Polysaccharides

Tollens test for Aldoses

Silver mirrorMolisch Test: a color reaction

Carbohydrates are hydrolyzed by sulfuric acid then the monomers are dehydrated to furfural Positive: purple ring at the interface of two liquidsBenedicts Test: test for reducing sugars

Of the sugar tested, only sucrose gave a negative for benedicts test while the hydrolysate of sucrose is positive. Why?

Osazone Formation

Yellow crystalline solid

Useful for identifying simple sugars (time for the crystals to appear)SampleTime for osazone formationFructose2 minGlucose4-5 minLactoseSoluble in hot waterSucrose30 min (hydrolysis)EpimersPair of diastereomers that differ only in configuration at only a single tetrahedral chirality center.

mannose and glucose are C2 epimers

Killiani- Fischer synthesis

Ruff Degradation

Glycosidic linkages of Disaccharides vs

Experiment 9ACYL COMPOUNDS: SOAPS AND DETERGENTSAcyl Compounds: Carboxylic Acid Derivatives

Acyl Substitution: Nucleophilic Addition- Elimination at the Acyl CarbonThe result: substitution at the acyl carbonKey mechanism: formation of a tetrahedral intermediate

Acyl Substitution: Nucleophilic Addition- Elimination at the Acyl CarbonSpecific Example:

Relative Reactivity of Acyl CompoundsAcyl chlorides are the most reactive toward nucleophilic addition- elimination and amides are the least reactive.

General Synthesis

Acidity of Acyl CompoundsCarboxylic acids are acidic compounds that can react with a base. (Bronsted- Lowry base)

Strong acidsSoluble in both NaOH and NaHCO3Weak acidsSoluble in NaOH but not in NaHCO3Sulfonic acids R-SO3HCarboxylic acids RCOOH

Phenols (Ar-OH)Hydrolysis of Acyl CompoundsProduct: carboxylic acid and the leaving group w/ hydrogen

Soap FormationCooking oilSoap is formed thru base hydrolysis of cooking oil.The process is called saponification Detergent

Sulfated Alkylated to be more environmentally friendly (biodegradable and soluble)

Soap and detergents have the same action on dirt. It creates micelles where the dirt (grease) is dissolved by the non polar tail and the polar head projects outward to dissolve in water

Reaction with soft and hard water.Detergents offer an advantage over soaps because they function well in hard water. They dont produce scum in hard water. Calcium, iron and magnesium salts of alkanesulfonates and alkyl hydrogen sulfates are largely water soluble. Soaps, by contrast, form precipitates, the ring around the bathtub, when they are used in hard water.

Emulsifying ActionBoth are able to emulsify two insoluble liquids because both have polar and non- polar moiety in the molecule.

Experiment 10AMINES, AMINO ACIDS and PROTEINSGeneral Structure

Amines (1, 2, 3)

Solubility of amine compoundsAmines (5