Synthesis of unsaturated [1,2]oxazines by using sigmatropic rearrangements and the ring-closing metathesis reaction

Various substituted unsaturated [1,2]oxazines have been synthesized by using a [2,3]- or a [3,3]-sigmatropic rearrangement and a ring-closing metathesis reaction as key steps.     

Emission spectrum of CO2 in the 9.6 μm region

The emission spectrum of ¹²C¹⁶O₂ in the 9.6 μm region has been observed with a high resolution spectrometer. The 00⁰-02⁰0 transition appears with a high intensity. Some additional transitions have also been observed and effective rotational constants for the corresponding bands have been calculated. Because of the overlapping of some “hot” lines with the principal ones, care has to be taken in using the 00⁰1–02⁰0 transition as reference for calibration of high resolution spectra.