New polyesters with basic units containing 6, 7, 8, 9, 10, 13, and 14 chain atoms have been prepared from levo-2,3-butanediol and ethyl oxalate, ethyl malonate, dimethyl terephthalate, maleic anhydride, succinic, glutaric, adipic, azelaic, and sebacic acids, and from meso-2,3-butanediol and o-phthalic anhydride. Esterification of 2,3-butanediol with a dibasic acid, or its anhydride, is accompanied by a side reaction, in which butanone-2 and the cyclic methyl ethyl ketal are formed. The purified polyesters, with the exception of the poly-malonate, appear to be composed of regularly recurring acid and diol segments over the molecular weight ranges investigated. Without exception they are amorphous resins or balsams. Polyesters formed from saturated aliphatic dibasic acids become progressively softer as the number of methylene groups in the acid segment increases. The polymeric oxalate, on distillation in vacuo, is converted to a macrocrystalline cyclic monomer.
Oxidation with Nitrogen Trioxide of Ethyl Malonate into Ethyl Dioxymalonate
