DMPM (3,4-dimethoxybenzyl) protecting group for hydroxy function more readily removable than MPM (P-methoxybenzyl) protecting group by DDQ oxidation

The DMPM (3,4-dimethoxybenzyl) protection for hydroxy function was deprotected more readily than the MPM (p-methoxybenzyl) protection by DDQ oxidation under neutral conditions, and applied to the synthesis of some synthons to macrolide and polyether antibiotics.     

Heating and quenching of metastable superconducting compounds with a plasma jet

Superconducting compounds, such as cubic -MoC_1–x, cubic -WC_1–x, hexagonal MoB₂, and cubic -TaN, which are metastable at room temperature, have been formed by heating and quenching of their respective equilibrium phases, such as hexagonal -MoC_1–x, hexagonal WC, rhombohedral Mo₂B₅, and hexagonal -TaN in a plasma jet. From calculations based on a simple model, the quenching rate of particles has been estimated to be 10⁵ deg s^–1.     

Formation and transformation of Pb2SiO4

A new modification of Pb₂SiO₄ was formed by the simultaneous hydrolysis of lead and silicon alkoxides, followed by washing and drying. It has a     

Reaction kinetics of multiphoton excited BCI3 with H2S

In order to investigate unique behaviors in kinetics of the reaction of multiphoton excited BCl₃ with H₂S, two kinds of experiments were performed. The first, parallel beam experiment, gives the activation energy of the primary reaction pathway considerably smaller than the bond strength. The second, focussed beam experiment, shows that the isotope selectivity increase with incident pulse energy. Both results were found different from typical multiphoton dissociation experiments, showing its own characteristics.     

Copolymerization of propylene with acrylate by a Ziegler-Natta type catalyst

Propylene was polymerized by using a Ziegler-Natta type catalyst in the presence of ethylchloroaluminum acrylate, which was formed by the reaction of diethylaluminum chloride with acrylic acid. The polymer obtained contained acrylic units which were proved to be copolymerized with propylene units by solvent extraction, infrared spectrum, and NMR spectrum. The copolymer showed much improved properties compared with the polypropylene homopolymer.