ABSTRACT
Section 16.3; Chapter 18, Sections 18.1, 18.3 and 18.4, 18.6 and 18.7) • formation of Grignard reagents and organolithium reagents
(Chapter 15, Sections 15.1 and 15.2, 15.5) • structure and reactivity of organocuprates (Chapter 15,
Section 15.6) • structure and characteristics of carbocations (Chapter 7, Section
7.4.1; Chapter 10, Section 10.2) • factors that contribute to acidity (Chapter 6, Section 6.3) • factors that contribute to basicity (Chapter 6, Section 6.4) • reversible reactions and reaction energetics (Chapter 7, Sections
7.5 and 7.6, 7.10) • fundamentals of kinetic and thermodynamic control (Chapter
22, Section 22.4.2) • concept of resonance and resonance stability, and how to draw
resonance contributors (Chapter 5, Section 5.9.3; Chapter 18, Section 18.6; Chapter 21, Section 21.3; Chapter 22, Section 22.2)
• rate of reaction (Chapter 7, Section 7.11) • E-and Z-stereoisomers (Chapter 9, Section 9.4) • how to identify polymers (Chapter 10, Section 10.8.3)
This chapter discusses dienes and alkene-ketones, alkene-aldehydes, or alkene-esters with a particular emphasis on those molecules that are conjugated. In conjugated molecules, the π-bonds are directly connected with no intervening sp3 atoms. Conjugated dienes react similarly to other alkenes; however, due to conjugation, the intermediates formed from conjugated dienes are resonance stabilized. Such resonance-stabilized intermediates lead to differences in product distribution when compared to simple alkenes. An alkene unit may also be conjugated to ketones or aldehydes, and conjugated carbonyl compounds exhibit reactions different from those of nonconjugated ketones
or aldehydes. Conjugated systems interact with ultraviolet (UV) light in ways that are different from interactions of nonconjugated compounds, and the UV spectra are used to identify conjugated compounds.
