Destructive sample rotation

Irradiation performed with racemic substrate at room temperature, unless noted otherwise. Anisotropy (g) factor at or around irradiation wavelength, if reported or estimated. Extent of destruction. Maximum observed rotation a of irradiated solution, or specific rotation [a] of isolated sample or of residue obtained upon evaporation. Maximum observed ellipticity of irradiated solution or molar ellipticity of isolated sample. Enantiomeric excess of isolated sample. Not reported. Compound (mp 113 C) of unknown structure, obtained in a reaction of humulene with sodium nitrite, according to the reported procedure Chapman, AC. J. Chem. Soc. 1895 67 780. A mixed case of asymmetric destruction and photoderacemization irradiation performed at 0 C. Enantiomerically enriched sample used. Estimated g factor enhanced by two-quantum excitation with high intensity picosecond laser pulse. High-inten-sity laser of indicated pulse duration used. "Irradiation performed at 77 K in a hydrocarbon glass matrix. Optically pure sample photolyzed only to evaluate the enhanced g factor. Estimated g factor enhanced by two—quantum excitation with high-intensity femtosecond laser pulse. 

Another point of uncertainty in interpreting these results is that the nature of the structure which was destroyed in melting, and whose heat of destruction was measured, was probably determined by the process of manufacture of the gelatin, and in particular by the chilling before the material was dried. The importance of previous history of dried samples will be shown in the discussion of optical rotation and swelling, pages 32 and 37. 

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