2,3,4-FURANTRIONES

This chapter focuses on the synthesis of heterocycles from 2, 3, 4-furantriones (2, 3-dioxobutyrolactones). It describes the synthesis of the furantriones and also considers their nitrogen derivatives, which retain the furanone ring and are mostly the starting precursors for the heterocycles in the third and fourth parts. The heterocycles that retain the furanone ring and those that are produced by its rearrangement are also dealt with respectively. The synthesis of compounds possessing the furantrione ring is based essentially on the ready oxidation of the hydroxy tetronic acids. The chapter discusses the nitrogen derivatives of furantriones. The heterocycle may be fused to the furanone ring at various positions. Thus, the fusion may be on C-5 and C-4, C-4 and C-3, or C-3 and C-2. Otherwise the heterocycle may be linked to the C-5 of the furanone ring. Heterocycles from rearrangement of the furanone ring are also discussed. © 1992 Academic Press Inc.