Tài liệu Bài giảng organic chemistry chapter6

ORGANIC CHEMISTRY Dr Nam T. S. Phan Faculty of Chemical Engineering HCMC University of Technology Office: room 211, B2 Building Phone: 38647256 ext. 5681 Email: [email protected] 1 Chapter 6: CONJUGATED ALKADIENES A non-polar molecule 2 Reactions of isolated dienes are just like those of alkenes 3 4 NOMENCLATURE OF ALKADIENES 5 6 PREPARATION OF 1,3-ALKADIENE Dehydrogenations Eliminations of unsaturated alcohols & alkyl halides 7 ELECTROPHILIC ADDITION REACTIONS 8 9 Reaction mechanism: 10 11 12 DIELS-ALDER REACTIONS 13 Reactivity of the dienophile is increased if 1 or more electron-withdrawing groups are present Partial positive charge 14 Stereochemistry Racemic mixture 15 In order to participate in a Diels-Alder reaction, the diene must be in an s-cis conformation C1 & C4 are too far apart to react with the dienophile 16 17 Polymerizations 18