The invention relates to hydrogel compositions, which can be applied as biodegradable materials and to the processes to prepare such hydrogels. The hydrogel of the present invention comprises a stereocomplex gel structure which is the result of the interaction of oligomerized monomers of one chirality with that of oligomerized monomers of the opposite chirality, both grafted to hydrophilic polymers. The grafts form an interaction which is different from a covalent chemical interaction and thus provide the gel with the required coherence.
Asymmetric synthesis of (s)-methyl-3-hydroxyalkanoates from ketene and 2,2-dichloroaldehydes via 4-(1,1-dichloroalkyl)-2-oxetanones