Organic Chemistry II: Reactivity, Synthesis, Spectroscopy - Problem Set 2 | CHEM 30B, Assignments of Organic Chemistry

Download Organic Chemistry II: Reactivity, Synthesis, Spectroscopy - Problem Set 2 | CHEM 30B and more Assignments Organic Chemistry in PDF only on Docsity! Chem 30B Problem Set II 1-22-02 Reactions of Alkenes It is good practice to work through reactions you are not familiar with. If a question addresses a reaction that has not been presented in lecture or the text, feel free to skip it, but if you have time you should at least make an attempt. 1) What will be the major product of the reaction of 2-methyl-2-butene with each of the following reagents? (Hint: even if you are unfamiliar with a set of reagents, you can draw out the general mechanism for addition to alkenes to figure it out) a. HBr b. HBr + Peroxide c. HI d. ICl e. H2/Pd0 f. HBr + excess NaCl g. Hg(OAc)2, H2O followed by NaBH4/HO- h. H2O + trace HCl i. Br2/CCl4 j. Br2/H2O k. Br2/CH3OH l. BH3/THF followed by H2O2/HO- m. Hg(O2CCF3)2, CH3OH followed by NaBH4/HO- 2) When 3-methyl-1-butene reacts with HBr, two alkyl halides are formed, 2-bromo- 3-methylbutane and 2-bromo-2-methylbutane. Propose a reasonable mechanism that accounts for the formation of these products. 3) Provide the reagents necessary to convert allyl-cyclohexane to each of the following: a. Br Br e. OH Br b. f. OCH3 c. Br g. OH d. Br h. OH 4) How could you prepare the following compounds starting from any alkene and any other reagents? a. d. OH b. Cl e. Br OH c. Br f. Br Cl Carbocations I have grouped radicals with carbocations because their behavior is similar, so remember that some of these reactions involve radicals, and some carbocations. 5) Propose a mechanism for the following reaction: Br HBr + Br a. Is the initially formed carbocation 10, 20, or 30? b. Is the rearranged carbocation 10, 20, or 30? c. Why does this rearrangement occur at all? 6) Propose a mechanism for each of the following reactions: a. H2SO4OH O b. (Hint: R2O2 + 2HCCl3 2 CCl3 + 2 ROH)R2O2 HCCl3 CCl3