CHEM 3331 1nd Edition Lecture 25Outline of Last Lecture I. OxidationII. Biological oxidationIII. Formation of sulfonate estersIV. Reduction of alcoholsV. Reactions of alcohols with HXOutline of Current Lecture I. Reactions with PX3 or PX5II. Reaction with thionyl chlorideIII. DehydrationIV. Reactions of diolsV. Formation of estersCurrent LectureI. Reactions with PX3 or PX5We have already seen ROH +HX RX +H2O3ROH + PCl3/PBr3 H3PO3 +RCl/Br and 6ROH + 2P +3I2 6RI + 2H3PO3This works well with primary and secondary alcohols, but due to their steric bulk it is best to useHX for tertiary. These reactions also create a liquid side product H3PO3. II. Reaction with thionyl chlorideTo eliminate any side products being formed we use thionyl chloride (SOCl2).ROH + SOCl2 RCl + SO2 + HCl. The two byproducts are gases so they escape into the air leaving behind only the RCl. These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.III. DehydrationROH + H3O+ ROH2 + H2O (R)2C=C(R)2When H3O+ is introduced it adds a hydrogen to the existing alcohol making OH2. This gives a positive charge to the oxygen so it leaves leaving behind a positive charge on the carbon. When the remaining H2O is reintroduced the adjacent hydrogen atom is swept up by it and allows for a double bond to form connecting to the positive charge. Thus creating an alkene.This is an E1 reaction.ROH + H+ ROH2+ ROH RO+-H,-R (-H+) ROR2ROH + H+ H2O + ROR 2 molecules:2 molecules this reaction is not temperature dependent.ROH + H+ ROR + alkene 1 molecule:2 molecules this reaction is temperature dependent so you will form more products with a higher temperature.IV. Reactions of diolsAn example of this would be the pinacol rearrangement. From (CH3)2COHCOH(CH3)2 to CH2C=OC(CH3)3. Another example is the use of HIO4 on a diol it creates double bonds onto oxygen opening the ring up. It is similar to ozonolysis on an alkene.V. Formation of estersEsters contain a double bond to an oxygen and also an oxygen between two carbons.They smell good and are components of flavor in fruit. Synthetic esters are used in flavoring.Inorganic esters, such as dimethyl sulfate or ATP or hydroxylamine.Hydroxylamine is what is used to create TNT, nitrocellulose, nitroglycerine, and finally dynamite.Which Alfred Nobel created believing it would be used for good and to help tear down old building so new ones could be made. Thus when it was used for harm he created the Nobel Prize. ROH +NaNH2 (-NH3) RONa + R’Br ROR’ROH +Na˚ (-H2) RONa + R’Br
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