Phase Separation Phenomenon in Non-ionic Surfactant TX-114 Micellar Solutions: Effect of Added Surfactants and Polymers

Clouding (or phase separation) in non-ionic surfactants is a well-known phenomenon. Clouding is to be avoided in some applications whereas in others it is preferred. Herein the results of CP (cloud point—the temperature at which solution separates into two phases) measurements of the non-ionic surfactant Triton X-114 (TX-114) in the presence of surfactants and polymers are presented. Cationic and nonionic surfactants, in the absence and presence of the quaternary salt tetrabutylammonium bromide (TBAB), increase the CP of TX-114. Anionic surfactants, in the absence of TBAB, increase the CP; in the presence of TBAB, these surfactants decrease the CP. Polymers of PEG and PVP series have been found to decrease the CP. The results are discussed by taking into consideration the nature of the added surfactants and polymers.     

Chiral Lewis Base-Catalysed Asymmetric Syntheses of Benzo-fused ϵ-Lactones

We herein report a two-step protocol for the asymmetric synthesis of novel chiral benzofused ϵ-lactones starting from O-protected hydroxymethyl-para-quinone methides and activated aryl esters. By using chiral isothiourea Lewis base catalysts a broad variety of differently substituted products could be obtained in yields of around 50 % over both steps with high levels of enantioselectivities, albeit low diastereoselectivities only.