organic compounds
The photochemistry and crystal structures of four α-adamantylacetophenones have been studied, namely, 1-(4-fluorophenyl)-2-(tricyclo[3.3.1.13,7]dec-1-yl)ethanone [(1a), C18H21FO], 1-(4-cyanophenyl)-2-(tricyclo[3.3.1.13,7]dec-1-yl)ethanone [(1b), C19H21NO], 1-(4-cyanophenyl)-2-(3-methyltricyclo[3.3.1.13,7]dec-1-yl)ethanone [(1c), C20H23NO] and 1-(4-carboxyphenyl)-2-(3-methyltricyclo[3.3.1.13,7]dec-1-yl)ethanone [(1d), C20H24O3]. All four molecules adopt fairly similar conformations, with short γHO contacts permitting hydrogen abstraction in the photochemical reactions. However, three of the compounds, (1a), (1b) and (1d), are photostable in the solid state and possible reasons for this unreactivity are considered.