Cycloaddition Reactions of Heptafulvenes: An Overview
31 December 2000 (online)
Heptafulvenes exhibit multiple reaction profiles in cycloaddition reactions. 8-Alkyl and 8-alkoxy heptafulvenes are shown to be excellent 8π partners with electron deficient dienophiles. Heptafulvene chromium carbonyl complex undergoes [6 + 4] addition with butadiene. The [4 + 2] cycloaddition reactions of heptafulvenes yield complex bicyclo systems. Isolated examples of heptafulvene participating as a 2π addend are also reported. Cyclohepta[b]furan-2-one, a tethered heptafulvene derived from tropolone, undergoes both [8 + 2] and [4 + 2] additions.
heptafulvenes - 2H-cyclohepta[b]furan-2-ones - cycloaddition profiles