CHM 2211 Lecture Notes - Lecture 2: Heteroatom, Absorbance, Golf Ball
Document Summary
Diels-alder reactions: rules: the diene can react only when it adopts the s-cis conformation (very reactive). If not, it will not react (very unreactive): electron-withdrawing substituents in the dienophile increases the reaction rate, the stereochemistry of the dienophile is retained. If dienophile is cis, product is cis; either one cis (both in dashes) or the other cis conformation (both in wedges). If dienophile is trans, product is trans; we get two trans products. If we have a 1,3-diene and a ring for a dienophile, we get two fused rings: fused because the carbons are connecting the rings together, product is called fused bicyclic system. If we have a diene that is cyclic, then the product is different: product is called bridged bicyclic system, preference for endo orientation. If dienophile has heteroatom, heteroatom can have endo or exo orientation: endo down, exo sideways.