SYNTHETIC APPROACHES TO EITHER HOMOCHIRAL OR ACHIRAL DERIVATIVES OF 3-HYDROXY-2(5H)-FURANONE (ISOTETRONIC ACID)

Several title compounds were synthesized according to new methods base d either on the use of D-ribonolactone as a chiral precursor or on the cyclization of 2,4-dioxopentanoic acid as a suitable achiral precurso r. Base-induced elimination and subsequent acid-promoted ring contract ion is an efficient protocol for the preparation of isotetronic acids from 2-O-alkyl-3,4-O-benzylidene-D-ribono-1,5-lactone derivatives.