Abstract The synthesis of a series of 6, 6-bisbenzannulated spiroketals containing a 3H, 3′ Η-2, 2′-spirobi (benzo [b][1, 4] dioxine) ring system is reported. The key step involves addition of a monobenzyl-protected catechol to the epoxide unit of a glycidol bearing a benzyl-protected catechol. The resultant alcohol adduct is oxidized to a ketone that then undergoes hydrogenation and acid-catalyzed cyclization to produce the desired ...
