DIELS-ALDER REACTION OF 4, 6-DIHYDROTHIENO[3, 4-c]FURAN-5, 5-DIOXIDE WITH QUINONES : STEREOSELECTIVE SYNTHESIS OF QUINONE-ANNELATED 2, 3-BIS(METHYLENE)-7-OXABICYCLO[2.2.1]HEPTANES

Abstract

4, 6-Dihydrothieno[3, 4-c]furan-5, 5-dioxide (1), a novel precursor of a bis-diene, reacts with quinones to afford the normal Diels-Alder adducts, the quinone-annelated 2, 3-bis (methlene)-7-oxabicyclo[2.2.1]-heptane derivatives. Promising building blocks(3b and 5) for the synthesis of the antineoplastic antibiotics are prepared by this method.