The circular dichorism spectrum (Figure 1) of the optically active (lS)-2,4-adamantanedione-4-'80 (7) is characterized by three bands at 320, 307, and 297 nm
and small bands at lower wavelength. No immediate conclusion should be drawn about
the considerable differences between the CD spectrum of 7 and that of the only other
two optically active rigid 1,3-diketone~,~J~ since temperature and solvent effects can
influence these spectra strongly as has been clearly demonstrated by LightneP and was found for 7.19 It is reasonable to assume that the bands belong to different electronic transition.