7) Which of the following compounds is the most reactive dienophile in a Diels-Alder reaction with 1,3-butadiene? A) CH2-CHOCH3 B)CH2CHCHO C) CH3CH-CHCH3 D) (CH3)2C-CH2 E) CH2-CH2 Haiiawi, A

C341 5.) Draw a step-by-step mechanism for the reaction of 1-methyl-1-cyclopentene with the following: a.) hydrogen bromide (i.e., hydrohalgenation) H-Br b.) Br2 in CH2Cl2 (i.e., halogenation) Br-Br c.) Br2 in ethanol (i.e., halohydrin) Br Br OH Chapter 8: Alkenes

Draw the structure of the product of the Diels-Alder reaction below. CH3 O Visited (+ CH3 90-85 + • Use the wedge/hash bond tools to indicate stereochemistry where it exists. Include H atoms at chiral centers only. • If a group is achiral, do not use wedged or hashed bonds on it. • If the reaction produces a racemic mixture, just draw one stereoisomer. CH3OC-C=C-COCH3 O [ ] در ? Previous Frail Instructor Save

What is the possible products for following compound with one equivalent of HBr? 3,4 dimethyl-hepta-2,4-diene a) 3 bromo-4,5-dimethyl hepta-3-ene and 4- bromo-3,4-dimethyl hepta-2- ene b) 3 bromo-3,4-dimethyl hepta-3-ene and 4- bromo-3,4-dimethyl hepta-3- ene c) 3 bromo-4,5-dimethyl hepta-2-ene and 3- bromo-3,4-dimethyl hepta-2- ene d) 3 bromo-4,5-dimethyl hepta-3-ene and 4- bromo-3,4-dimethyl hepta-3- ene e) 3 bromo-4,5-dimethyl hepta-3-ene and 2- bromo-3,4-dimethyl hepta-2- ene O a. e O b. b O c.d O d. c O e. a