Organic Chemistry II Dr Christopher Cioffi Monday 3202017
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- Slides: 46
Organic Chemistry II Dr. Christopher Cioffi Monday 3/20/2017 9: 00 AM – 9: 50 AM
Dienes and Conjugation
Dienes and Conjugation
Dienes and Conjugation
Dienes and Conjugation Which systems are conjugated? Which ones are not conjugated?
Which systems are conjugated? Which ones are not conjugated?
The Diels-Alder Reaction
The Diels-Alder Reaction
The Diels-Alder Reaction: Highlights § Pericyclic reaction § A concerted (one-step) reaction that proceeds via a cyclic transition state § [4+2] Cycloaddition reaction between a conjugated diene an dienophile § Forms six-membered ring systems (cyclohexene products) § Generates molecular complexity efficiently § Accommodates several functional groups, generates a new double-bond, and con stereochemistry and regiochemistry: can establish up to four stereogenic centers
The Diels-Alder Reaction: Use in Total Synthesis cortisone prostaglandin taxol 1. J. Am. Chem. Soc. 1952, 74, 4223 -4251. 2. J. Am. Chem. Soc. 1969, 91, 5675 -5677. reserpine
The Diels-Alder Reaction: Highlights § Active Pharmaceutical Ingredients (APIs) § Agrochemicals § Flavors and fragrances Funel, J. A. ; Abele, S. ; Industrial applications of the Diels-Alder reaction. Angew. Chem. Int. Ed. Engl. 2013, 52, 3822 -3863.
The Diels-Alder Reaction: A [4+2] Cycloaddition
The Diels-Alder Reaction: A [4+2] Cycloaddition
The Diels-Alder Reaction: [4+2] Cycloaddition § The reaction involves 4 -p electrons of the diene and 2 -p electrons of the die § Converts two p-bonds into two s-bonds § Concerted reaction: all bond breaking and bond making happens simultane a single step
The Diels-Alder Reaction: Requirements
The Diels-Alder Reaction: Electronics Requirements Which diene is least reactive? Which diene is most reactive? Why?
The Diels-Alder Reaction: Electronics Requirements Which diene is least reactive? Which diene is most reactive? Why?
Which dieneophile is least reactive? Which dieneophile is most reactive
Which dieneophile is least reactive? Which dieneophile is most reactive?
Which of the following are expected to be good Diels-Alder dienophiles?
Which of the following are expected to be good Diels-Alder dienophiles?
Diene Requirement: Conjugation and s-Cis Conformation
Diene Requirement: Conjugation and s-Cis Conformation
How would you rank the reactivity of the following dienes?
How would you rank the reactivity of the following dienes?
The Diels-Alder Reaction: Mechanism
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry
The Diels-Alder Reaction: Mechanism and Syn Stereochemistry Rac
Regioselectivity: 1, 4 - and 1, 2 -Products
The Diels-Alder Reaction: Pushing and Pulling Electrons via Re
The Diels-Alder Reaction: Pushing and Pulling Electrons
The Diels-Alder Reaction: Pushing and Pulling Electrons Can you predict the Diels-Alder Products?
The Diels-Alder Reaction: Pushing and Pulling Electrons Can you predict the Diels-Alder Products?
The Diels-Alder Reaction: The Endo Rule
The Diels-Alder Reaction: The Endo Rule
The Diels-Alder Reaction: The Endo Rule
The Diels-Alder Reaction: The Endo Rule
The Diels-Alder Reaction: Use in Total Synthesis cortisone prostaglandin taxol 1. J. Am. Chem. Soc. 1952, 74, 4223 -4251. 2. J. Am. Chem. Soc. 1969, 91, 5675 -5677. reserpine