Die reaktion von 2.6-dimethylnaphthalin mit diazoessigester

Thermal decomposition of ethyl diazoacetate in 6 molar equivalents of 2.6-dimethylnaphthalene yielded 58 per cent of carbethoxycarbene monoadducts which comprise 74 per cent ethyl 2.6-dimethyl-1a.7b-dihydro-1H-cyclopropa[a]naphthalene-(1)-carboxylate (VI), 15 per cent of the isomeric 1b.5-dimethyl compound VIII and 9 per cent of ethyl 2.7-dimethyl-5H-benzocyclohepten-(6)-carboxylate (X). The higher boiling fraction of the product contained 11 per cent of diadduct XXIV. These compounds were structurally elucidated, especially by oxidation and hydrogenation, and were characterised by U.V. and I.R. spectra. The partial rate factors of carbethoxycarbene addition, with reference to the 1.2-bond of naphthalene taken as 1.0, were 1.4 for the 1.2-bond and 4.2 for the 3.4-bond of 2.6-dimethylnaphthalene.     

Eine einfache apparative Anordnung zur emissionsspektroskopischen 15N-Bestimmung im Mikromaßstab

A simple device for emission-spectroscopic ¹⁵N determination with photoelectric recording is described. The nitrogen is stimulated for light emission in glass tubes between capacitor plates of an oscillator circuit. The frequency is regulated to 13.9 MHz by means of a high frequency generator (DX-60, Heathkit) with an effective power of 15–20 W. The dispersion and detection of the emitted light is performed by a Zeiss Spectrophotometer PMQ II, used with a wave-length scanner and a recorder.     

ω-Hydroxyalkyl-phosphonium salts as “instant-ylid” components : extremely convenient and highly cis-selective synthesis of alkenol-type pheromones

In less than 2 hours, (Z)-alkenols of 97 – 98% stereoisomeric purity may be prepared and isolated (!) if a new type of “instant-ylids” is used.