Homework 5 - Answers - Homework Problem Set 5 Iverson...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 NAME (Print): _____________________________ SIGNATURE: _____________________________ Chemistry 310N Dr. Brent Iverson 5th Homework February 22, 2007 Please print the first three letters of your last name in the three boxes Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 Score: _________ Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (4 pts each) Write the IUPAC name for each molecule on the line provided. O OH O 2-Oxoheptanoic acid O OH (Z)-4-Phenyl-2-butenoic acid O HO CH3 Cl CH3 (3R,5S)-5-Chloro-3-methylhexanoic acid Draw a structure for the following molecule: (R)-2-Cyclohexyl-2-hydroxyacetic acid OH OH O Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (4 pts) Rank the following from weakest to strongest acid, with a 4 under the weakest acid and a1 under the strongest acid. O F F F OH O OH F O OH F F O OH 1 4 3 2 (2 pts each) Consider the following acid: OH OH O pKa = 3.08 In the space provided, draw the predominant form of this acid in water at pH 10.0 OH O O In the space provided, draw the predominant form of this acid in water at pH 7.0 OH O O In the space provided, draw the predominant form of this acid in water at pH 1.0 OH OH O Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (27 pts.) Complete the mechanism for the following cyclic acetal formation reaction. Be sure to show arrows to indicate movement of all electrons, write all lone pairs, all formal charges, and all the products for each step. H O O O H Cl (resonance) H O O H H O H O H H H O O H O R H O H H H H O O H O R O H O H O H O O O H R O (resonance) O H H R O H H "Sweet intermediate" O O H R O O H O H O O H R O H Product(s) Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (28 pts.) Complete the mechanism for Fischer esterification. Be sure to show arrows to indicate movement of all electrons, write all lone pairs, all formal charges, and all the products for each step. O H O H O O H O H O O H O H H O H H O H O O O H H O + H2 O O H O O H O H O H H H H O H O O H H O H O O H O H Products O H Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (3 or 5 pts each) Fill in the box with the product or products that are missing from the following chemical reaction equations. When a racemic mixture is formed, you must write "racemic" under both structures EVEN THOUGH YOU DREW BOTH STRUCTURES. For these draw all carbon containing products. Br Mg ether MgBr OH O 1) NaBH4 2) H2 O 1) CO2 2) HCl / H2O OH 1) LiAlH 4 2) H2 O l2 OC S OH O Cl O OH H 2SO4 (catalytic amount) OH OH H2CrO 4 (excess) O O OH O O heat CO 2 O Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 (3 or 5 pts each) Fill in the box with the product or products that are missing from the following chemical reaction equations. When a racemic mixture is formed, you must write "racemic" under both structures EVEN THOUGH YOU DREW BOTH STRUCTURES. For these draw all carbon containing products. OH racemic OH OH racemic OH excess H2 Pd OH racemic OH 1) LiAlH 4 2) H2 O O 1) NaBH4 2) H2 O Zn(Hg) O HCl H 2NNH2 NaOH excess Br 2 NaOH O + CHBr3 O Note how the carboxylate ion is formed, not the carboxylic acid, because no acid was added to the reaction in a second step! Homework Problem Set 5 Iverson CH310N Due Wednesday, February 27 These are synthesis questions. You need to show how the starting material can be converted into the product(s) shown. You may use any reactions we have learned. Show all the reagents you need. Show each molecule synthesized along the way and be sure to pay attention to the regiochemistry and stereochemistry preferences for each reaction. (15 pts) All of the carbon atoms of the products must come from the starting material for this one! ? 1) Hg(OAc)2 2) NaBH4 or H2O H2SO4 PCC OH Br or H2CrO4 O HBr ROOR P(Ph)3 nBuLi P(Ph)3 P(Ph)4 Recognize that the product is an alkene, indicating a Wittig reaction as the last step. This makes sense because the product has six carbon atoms, indicating that two molecules of the starting material were needed to create the product. Recognize that the acetone could be derived from propene through a combination of Markovnikov addition of water followed by oxidation. The Wittig reagent is available from non-Markovnikov addition of HBr in the presence of peroxides followed by the usual reaction with P(Ph)3 and n-BuLi. Note, there are actually two sets of reagents that would give this Wittig product. 1) BH3 2) H2O2 / HO H OH Br PCC O HBr P(Ph)3 P(Ph)3 nBuLi P(Ph)3 ...
View Full Document

Ask a homework question - tutors are online