Bisketene Equivalents as Diels-Alder Dienes.

2,5-Bis(-butyldimethylsilyloxy)furans are established as vicinal bisketene equivalents for application as dienes in the Diels-Alder reaction. Cycloaddition with olefinic dienophiles, under exceptionally mild conditions, enables convergent access to highly substituted -hydroquinones in unprotected form via a one-pot Diels-Alder/ring-opening/tautomerization sequence. The synthesis of -benzoquinones from acetylenic dienophiles, including benzynes, is also demonstrated, and 2,5-bis(-butyldimethylsilyloxy)pyrroles are established as competent dienes for the synthesis of -iminoquinones. Application in natural product synthesis enables gram-scale access to the neuroprotective agent (±)-indanostatin.