J3-propiolactone

A novel method consists in reacting a j3-propiolactone with 5-alkyl isothiouronium salts127 to give 2-imino-4-oxotetrahydro-l,3-oxazines. 

Solvent and Substituent Effects in the Anionic Polymerization of o ,Q -Disubstituted j3-Propiolactones... 

The j3-propiolactones 02N CF2 C(CF3) CH2 C0-0 and (CF3)2C CH2 C0"0 respectively have been used in work on compounds containing the CFs NOa group [see item (viiO, p. 246F and on the synthesis and ring-opening polymerization... 

A similar procedure, using highly viscous liquid complexes formed by FeClj (oxidant) with polymers such as poly(ethylene oxide) (PEO), poly(j3-propiolactone) (PPL) and poly(l,5-di-oxepan-2-one) (PDXO) was employed by Rabek et al [339] to fabricate P(Py) composites. The complexes were first prepared in dry nitro-methane (polymer FeClj ratio 7 3) and cast as films on glass. The films were then exposed to pyrrole vapor in a desiccator, yielding composites of 50 - 200 pm thickness over different reaction times. Excess oxidant and unreacted monomer were removed with a nitromethane wash. Conductivities were ca. 10 S/cm and transmissions below 50% in the mid-Visible region. 

---