Homework Problem Set 8 Iverson CH320M/328M Due Friday, Nov. 9

Transcription

1 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov. 9 NAME (Print): SIGNATURE: hemistry 320M/328M Dr. ent Iverson 8th omework November 2, 2018 Please print the first three letters of your last name in the three boxes 1

2 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov. 9 Score: 2

3 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov omplete the following intiation and propagation steps for the addition of via a free radical chain reaction mechanism. Use appropriate arrows to show movement of electron density, and show all nonbonding electrons as dots and show any formal charges. If any of the species are really a mixtures of enantiomers, you only need to draw one stereoisomer and write "" Initiation R O O R R O R O same species R O R O Propagation same species same species same species Products Termination Termination Products 3

4 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov Succintly define ammond's postulate. ammond's postulate says that the transition state for an exothermic step resembles the reactants more than the products of that step, and the structure of the transition state for an endothermic step resembles the products more than the reactants of that step. 3. For the following, complete the reactions with the predominant product or products. You must indicate stereochemistry with wedges and dashes. If a mixture is created, you must write "" under the structures. 2 2 not chiral 2 Meso (anti addition) 2 (reacts at more substituted atom) (not chiral) Think about this one!! NBS The most stable alkene removes the chiral center at methyl. 4

5 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov For the following, complete the reactions with the predominant product or products. You must indicate stereochemistry with wedges and dashes. If a mixture is created, you must write "" under the structures. (Assume NO rearrangement) (Assume rearrangement) 2 ROOR NBS 1) 3 NaN 2 2) l / 2 O Na 3 S N 2 5

6 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov For the following, complete the reactions with the predominant product or products. You must indicate stereochemistry with wedges and dashes. If a mixture is created, you must write "" under the structures. 2 (reacts at more substituted atom) not chiral 2 (anti addition) (Markovnikov) 1) (sia) 2 B O 2) 2 O 2 / O 6

7 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov For the following, complete the reactions with the predominant product or products. You must indicate stereochemistry with wedges and dashes. If a mixture is created, you must write "" under the structures. NBS (allylic halogenation) most stable alkene ROOR (non-markovnikov) O gso 4 2 SO 4 2 O O 2 Na N 3 (trans product) 7

8 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov The point of organic chemistry is synthesis, the conversion of starting molecules into different ones with a new structure and function. Each reaction you are learning should be thought of as a tool that allows you to create a desired type of molecule. These tools can be used in an almost infinite number of combinations to create truly interesting molecules. In the large boxes provided, draw the structures of the molecules indicated in this synthesis scheme. For smaller boxes next to the arrow, write the reagents needed to carry out the appropriate reaction. You may use any reactions we have learned provided that the product(s) you draw for each step is/are the predominant one(s). 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. You must draw all stereoisomers formed, and use wedges and dashes to indicate chirality at each chiral center. Write when appropriate. All the carbons of the product must come from carbons of the starting material.? Starting Material Final Product 2 2 NaN 2 NaOMe (E2) 2 8

9 omework Problem Set 8 Iverson 320M/328M Due Friday, Nov In the large boxes provided, draw the structures of the molecules indicated in this synthesis scheme. For smaller boxes next to the arrow, write the reagents needed to carry out the appropriate reaction. You may use any reactions we have learned provided that the product(s) you draw for each step is/are the predominant one(s). 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. You must draw all stereoisomers formed, and use wedges and dashes to indicate chirality at each chiral center. Write when appropriate. All the carbons of the product must come from carbons of the starting material.? Starting Material Final Product 2 2 / Lindlar s catalyst 2 NaN 2 9