Polarographic reduction of germanium

In a previous note the authors had reported the polarographic reduction of ravalent germanium. These observations were confirmed, and full data are presented here which show the two-step reduction of tetravalent germanium under the dropping mercury electrode, from ammoniacal-ammonium chloride solutions.     

An Efficient “One Pot” Synthesis of Isoflavones

Initial formation of deoxybenzoin 3 from phenyl acetic acid 1 and phenol 2 in the presence of BF₃.Et₂O followed by its treatment at room temperature with N, N'-dimethyl (chloromethylene) ammonium chloride, generated by reacting PCl₅ with DMF provides a mild and efficient route for a “one pot” synthesis of Isoflavones in high yields.     

Novel crown ethers from 7-deoxycholic acid

The synthesis of novel crown ethers 1 and 2 derived from the triol 5 by condensation with the ditosylates 6 and 7 respectively is described. Results of energy minimization and cation binding studies of 1 and 2 are also reported.     

An efficient synthesis of α-(trimethylsilyl)allenyl ketones

The title compounds may be prepared in a one-pot operation from propargylic chlorides and acetyltrimethylsilane.     

A comparison between Lanczos and moment methods

A simple procedure is suggested for generating the 2n - 1 Lanczos tridiagonal elements from the 2n - 1 moments of any hamiltonian with regard to a given starting vector. The numerical feasibility is studied in the quartic oscillator example.     

A double-wavelength nitrogen-laser-pumped dye laser

A narrow-band tunable double-wavelength dye laser with a bandwidth of 0.1 cm⁻¹ is described. The output at one of the wavelengths is found to be completely linearly polarized in the plane of incidence.     

DMAP catalyzed reaction of β-ketoesters and dimethyl acetylenedicarboxylate: efficient synthesis of polysubstituted benzenes and biaryls

A DMAP catalyzed tandem addition-cyclization-dehydration sequence involving dimethyl acetylenedicarboxylate and β-ketoesters leading to polysubstituted benzene/biaryl derivatives is presented.