Wr. Roush et Da. Barda, AN INTRAMOLECULAR DIELS-ALDER APPROACH TO THE SPIROTETRONIC ACID SUBUNITS OF THE QUARTROMICINS, Tetrahedron letters, 38(51), 1997, pp. 8781-8784
Three of the four diastereomeric spirotetronates (2, 19 and 24) corres
ponding to the quartromicins were synthesized by a sequence featuring
the intramolecular Diels-Alder reaction of 3. An olefin isomerization
pathway accounts for formation of the second most abundant cycloadduct
, 16. (C) 1997 Elsevier Science Ltd.