Enantioselective synthesis of d- and l-α-methylcysteine with hydantoinase

A scalable and cost-effective synthesis of d- and l-α-methylcysteine is described. A key step is d-selective cyclization of N-carbamoyl S-tert-butyl-d,l-α-methylcysteine catalyzed by hydantoinase. d-5-tert-Butylthiomethyl-5-methylhydantoin and N-carbamoyl S-tert-butyl-l-α-methylcysteine were obtained with excellent yield and optical purity, and these compounds were easily separated by filtration. After hydrolysis and cleavage of the tert-butyl group, d- and l-α-methylcysteine hydrochloride were obtained.     

Pressure induced heavy electron states in TmTe

We performed a spectromicroscopic measurement on TmTe single crystal with fractured surface in THz to visible regions (25 meV to 2.5 eV) at 300 K and at pressures up to 6 GPa by using a diamond anvil cell (DAC) at the spectromicroscopy station (BL43IR) of SPring-8 in the THz region and also at Kobe University in the IR–visible regions. At pressures above around 1 GPa, a prominent Drude-like structure due to the appearance of the conduction electrons was resolved in the reflection spectra. From the analysis of the spectra by a simple Drude model, we found that the pressure-induced metallic state behaves as a heavy electron system.