The formation of novel saccharinic acids, 2-C-(2-hydroxyethyl)tetronic acids, by alkaline degradation of leucrose

Two novel saccharinic acids, 2-C-(2-hydroxyethyl)erythronic and 2-C-(2-hydroxyethyl)threonic acids, were identified as their per(trimethylsilyl) derivatives by GLC-MS after alkaline degradation of leucrose (5-O-α-d-glucopyranosyl-d-fructopyranose). The identifications were supported by converting the acids into two different types of 1,4-lactones, that is, 3-(1,2-dihydroxyethyl)-3-hydroxydihydro-2(3H)-furanone and 3,4-dihydroxy-3-(2-hydroxyethyl)dihydro-2(3H)-furanone. The novel acids appear to be highly characteristic alkaline degradation products of (1 → 5)-linked hexose disaccharides, although several other hydroxy acids were formed and identified as well.