Scope and Limitations of Fulvene Syntheses. Preparation of 6-Vinyl-Substituted and-Functionalized Fulvenes. First Examples of Nucleophilic Substitution on a 6-( …
Very few 6-vinylfulvenes have previously been reported in the literature. In a few cases where Little's procedure (using pyrrolidine as base) has been employed, most enones undergo conjugate attack by the cyclopentadienyl anion followed by either a retroaldol reaction or dihydropentalene formation. In several cases, Diels-Alder reaction of the enone with cyclopentadiene occurs rather than condensation. We have found that in cases ...