Organic Reactions Volume 4 - Sciencemadness Dot Org

CHAPTER 2
THE DIELS-ALDER REACTION
ETHYLENIC AND ACETYLENIC DIENOPHILES
H. L. HOLMES
University of Saskatchewan
CONTENTS
PAGE
NATURE OF THE REACTION 61
Formation of Stereoisomeric Adducts 62
Formation of Structurally Isomeric Adducts 63
SCOPE AND LIMITATIONS 64
Dienes and Dienophiles 64
Ethylenic Dienophiles 65
a, /3-Unsaturated Carbonyl Compounds 65
Aldehydes 65
Acids and Acid Derivatives 67
Ketones 72
«,/3-Unsaturated Nitriles, Nitro Compounds, and SuIf ones 75
Allyl, Vinyl, and Belated Compounds 77
Acetylenic Dienophiles 79
Aldehydes 79
Acids and Acid Derivatives 79
Other Acetylenic Compounds 86
Side Reactions 86
SELECTION OP EXPERIMENTAL CONDITIONS 89
Comparison of Dienes 89
Comparison of Dienophiles 89
Reaction Conditions 89
EXPERIMENTAL PROCEDURES 90
Addition of Acrolein to Cyclopentadiene 90
Addition of 2,6-Dimethoxy~4~n-amylcinnamic Acid to Isoprene 90
Addition of Methyl 5-Bromo-7,8-dimethoxy-3,4-dihydro-l-naphthoate to
Butadiene 91
Addition of 1-Nitro-l-pentene to Cyclopentadiene 91
Addition of A 2 -Dihydrothiophene-l-dioxide to Cyclopentadiene . . . . . . 91
Addition of Vinyl Acetate to Cyclopentadiene 92
Addition of Ethyl Acetylenedicarboxylate to trans-trans-l,4?-dipheiiylbu.ta,diene
92
Addition of Methyl Acetylenedicarboxylate to Anthracene 92
60