Reactions of cannabinoid tosylhydrazones: Stereochemical aspects

Reactions of the epimeric 7-oxo-hexahydrocannabinol tosylhydrazone acetates (2a and4a) are described. Under aprotic basic reaction conditions followed by acetylation both compounds lead to the known Δ1⁷-tetrahydrocannabinol acetate (6); under protic conditions the axial isomer undergoes ring expansion (to7b), the equatorial one gives6.     

Ein kolloider Wärmeindikator. II

Zusammenfassung Erh?hung der W?rmeempfindlichkeit der Sulfit-Novokain-L?sungen. PhotographischeWiedergabe der Lloyd-Schichtungen, welche darin auftreten, wenn sie bei Vorhandensein eines Konzentrationsgef?lles erw?rmt werden. Deren Bildung wird eingeleitet durch eine stufenweise Aufw?rtsbewegung von L?sung, die durch die randliche Erw?rmung ein etwas geringeres spezifisches Gewicht erlangt hat. Dafür senkt sich die entsprechende Menge von kühlerer L?sung in der Mitte des Rohrs nach unten und schiebt sich als klare Schicht unter die trübe. Es mu? jedoch zugegeben werden, da? damit der Mechanismus der Schichtenbildung noch nicht in allen Einzelheiten gekl?rt ist. Die notwendige Annahme der Konvektionen beim Zustandekommen der Lloyd-B?nderung schlie?t nicht aus, da? ihre Bedeutung nach der Ausbildung stark zurücktritt. Verfestigung der Flüssigkeit durch Gelbildung kann gewisse Lloyd-B?nderungen dauernd erhalten.     

Use of 13C isotope shifts for assignment of deuterium labelling sites in 1,3-diphenylpropan-1-one

¹³C NMR spectroscopy was used for the unequivocal analysis of the mixture of products of RuCl₂[P(C₆H₅)₃]₃-catalysed transfer deuteriation of benzylideneacetophenone by (a) DCOONa/H₂O, (b) HCOONa/D₂O and (c) DCOONa/D₂O. Signal assignments in the ¹³C spectra were obtained mainly from the deuterium-induced ¹³C isotope shifts. The geminal ¹³C? ²H shift of the β-carbon of deuteriated 1,3-diphenylpropan-1-one is almost twice that for the α-carbon.     

Naturally occuring lactones and lactames—V: Halogenated β-keto esters as starting materials for the synthesis of tetronic acids

In an effort to improve and simplify the synthetic route to tetronic acids 15 differently substituted β-keto esters were investigated as potential starting materials. The β-keto esters were brominated and cyclised with 2·5 N KOH as cyclising agent. Tetronic acid and seven derivatives including the naturally occuring carolinic acid were obtained. In a number of cases products arising from a Favorskii rearrangment were isolated. The NMR spectroscopic data are discussed.     

Observation of splitting of the E2g mode and two-phonon spectrum in graphites

We have found the two-phonon mode of the disorder-induced line at 1370 cm^-1 for the single crystal and polycrystalline graphites having disorder. The degenerate E_2g mode of the D_6h symmetry for graphite is split for the disordered graphites, having frequencies at 1590 cm^-1 and 1627 cm^-1. Brewster angle measurements using lasers at 6328A and 10.6 μm yield n and k with good consistency even for surfaces with moderate roughness. Our results suggested that distortion of the crystal structure is present.