Galacturonsäurederivate. I. Galacturonate aus Acetyl‐ und Isopropyliden‐D‐galactopyranosen

Galacturonic Acid Derivatives. I. Galacturonates from Acetyl‐ and Isopropylidene‐D‐galactopyranoses Galacturonic acid derivatives to be employed as glycosyl donors in saccharide synthesis are prepared from galacturonic acid itself or from galactose. Various syntheses of 1,2,3,4‐tetra‐O‐acetyl‐D‐galactopyranuronic acids (6) with differently protected carboxyl group and attempts of their conversion into galacturonpyranosyl bromides are described. The starting materials were 1,2;3,4‐di‐O‐isopropylidene‐α‐D‐galactopyranose and acetylated galactopyranose derivatives, respectively.