Optical rotatory dispersion and circular dichroism studies. Part XXXIX. Cotton effects of halogen-substituted αβ-unsaturated ketones

Abstract

The Cotton effects of steroids containing αβ, or αβ, γδ-unsaturated ketone groups have been measured using o.r.d. and c.d. The presence of a halogen substituent in a vinylic position alters the Cotton effect of the long-wavelength n→π* transition by approximately 1 Δε unit. The substituent effect is consistent for a particular type but cannot be correlated with an octant rule.

The short wavelength π→π* Cotton effects are not greatly altered by halogen substitution.