CIDNP assisted assignment of carbon‐13 NMR lines in α‐tetralone and α‐indanone

The reversible abstraction of hydrogen from benzene‐1,3,5‐triol by photoexcited α‐tetralone or α‐indanone in solutions of methanol leads to CIDNP in the 13 C NMR spectra of these compounds. The information gained from the phase of the polarization in the CIDNP spectra is used to resolve the ambiguities in the assignment of the 13 C NMR lines for α‐indanone and α‐tetralone, arising from conflicting literature data. Chemical shifts for both compounds in methanol are reported. 2′‐Methylacetophenone does not exhibit CIDNP in the 13 C spectrum under similar conditions.