CHM 2211 Chapter Notes - Chapter 17: Max Iv Laboratory, Bromine, Electrocyclic Reaction
Document Summary
Reactions: classes of dienes, dienes: compounds that posses two carbon carbon double bonds. Conjugated: pi bonds are separated by one sigma bond. Isolated: pi bonds are separated by two or more sigma bonds: conjugated dienes, preparation: Can be prepared from allylic halides via elimination: bond lengths. A single bond in a conjugated diene is shorter than a typical c c single bond: stability. Conjugated double bonds are more stable than isolated double bonds: conformations of 1,3-butadiene. S-cis conformer: disposition of two pi bonds with regard to the connecting single bond is cis-like. S-trans conformer: disposition of two pi bonds with regard to the connecting single bond is trans like: equilibrium favors s-trans, mo theory, (skip this section, electrophilic addition, addition of hx across 1,3-butadiene. Reaction proceeds via markovnikov addition: 2 products are formed by 1,2-addition and 1,4-addition, 1,2-adduct: h and br are at these two positions, 1,4-adduct: h and br are at these two positions.
