Synthesis of γ-Spirolactones and γ-Spirolactams. Diels-Alder Adducts Based on a 9,10-Dihydro-9,10-ethanoanthracene Structure

Article abstract of DOI:10.1021/jo00275a031

Syntheses of a variety of γ-spirolactones and γ-spirolactams derived from Diels-Alder adducts of anthracene are described.Alkylation of the anion of nitrile 8 with a variety of electrophilic agents affords either C2,C3-substituted γ-spirolactones or C2- or C2,C3-substituted γ-spirolactams.Hydrogenation of 8 affords C2-substituted γ-spirolactams.Changes in relative stereochemistry occur during synthesis of the spirolactones, product sterochemistry being dependent upon temperature and reaction time.A sequence of reactions involving aldol-like condensations and reversible ring closures is suggested to account for the observed stereoselectivities.