REACTIONS OF POLYMERIZATION-RESISTANT 1,2-DITHIOLANES WITH LITHIATED OXYGEN HETEROCYCLES

Lithiated furans have been found to cleave the S-S bond of polymerizat ion-resistant 1,2-dithiolanes to give the ring opened products in good yields. In the case of lithiated benzofuran, the excess reagent react ed with the normal product to give a mixture. Lithiated dihydrofuran a nd dihydropyran gave the corresponding ring-opened products that rearr anged to spiro-1,3-dithianes during acidic workup. The reaction was ap plied to the selective synthesis of substrates for intramolecular Diel s-Alder reactions. (C) 1998 John Wiley & Sons, Inc.