Chapter 16.10, Problem 24CC

1A. Explain why solvents such as anhydrous diethyl ether or anhydrous tetrahydrofuran (THF) are not reactive with Grignard reagents. 1B. Draw the first step of the reaction mechanism when the Grignard reagent attacks benzophenone before the alkoxide is protonated to form the alcohol. In the mechanism, identify the partially positive and partially negative atoms in the reactants. Explain why these atoms have a partial charge. 1C. Write the mechanism for the reaction of phenyl magnesium bromide with 1) water and 2) acetone.

6. Select the incorrect statement conceming the reaction you conducted during the isomerization experiment. Choose one. H,CO. Brz, light H,CO. rOCH rOCH methylene chioride dimethyl maleate dimethyl fumarate A. The major intermediate formed during the reaction contains both a bromine atom and a radical. B. Bromine is added catalytically instead of stoichiometrically because the bromine radical is regenerated when the product is formed. C. After twenty minutes, the reaction mixture contained both reactant and product. D. Both reactant and product are soluble in methylene chloride. E. If the reaction mixture turned colorless, that was an indication that the bromine radicals were consumed. F. When cold hexanes was added, only dimethyl fumarate precipitated out of solution because dimethyl maleate is soluble in cold hexanes.

As we will learn in Section 15.12, many antioxidants-compounds that prevent unwanted radical oxidation reactions from occurring-are phenols, compounds that contain an OH group bonded directly to a benzene ring. a. Explain why homolysis of the O-H bond in phenol requires considerably less energy than homolysis of the O-H bond in ethanol (362 kJ/mol vs. 438 kJ/mol). b. Why is the C-O bond in phenol shorter than the C-O bond in ethanol? -O-H CH,CH2-0-H phenol ethanol