Traceless linkers for solid-phase synthesis. Homo- and hetero-Diels-Alder reactions of o-quinodimethanes

The synthesis and Diels-Alder reactions of a polymer-supported o-quinodimet hane are described. Reaction with dimethyl acetylenedicarboxylate, benzoqui none and trichloroacetonitrile as dienophiles gives respectively substitute d naphthalenes or an isoquinoline off-resin, whilst reaction with aldehydes and imines gives polymer-supported benzodihydropyrans and tetrahydroisoqui nolines. The latter heterocyclic products undergo Lewis or Bronsted acid-me diated cleavage reactions which allow incorporation of further functionalit y at the point of cleavage whilst leaving no trace of attachment to the pol ymer support.