Propose a structure for D (molecular formula${\mathbf{C}}_{\mathbf{9}}{\mathbf{H}}_{\mathbf{9}}{\mathbf{ClO}}_{\mathbf{2}}$ ) consistent with the given spectroscopic data.

${}^{\mathbf{13}}\mathbf{C}$NMR signals at 30,36,128,133, 139, and 179 ppm

You can determine the structure of the compounds based on the spectroscopic data. The ${}^{13}C$NMR data determines the different types of carbon atoms present in the compound under investigation.

The ${}^{\mathbf{13}}\mathbf{C}$NMR is the application of the NMR spectroscopy and is used to investigate the structure of the organic compounds.

The compound with the molecular formula ${\mathrm{C}}_9{\mathrm{H}}_9{\mathrm{ClO}}_2$has five degrees of unsaturation. The seven different peaks of the ${}^{13}\mathrm{C}$NMRsuggest the presence of seven different types of carbon atoms.

The triplet at 2.7 ppm suggests the presence of two hydrogen atoms. The triplet at 2.9 ppm shows the presence of two hydrogen atoms, each adjacent to two other hydrogen atoms.

The two signals at 7.2 ppm suggests the presence of four hydrogen atoms on the benzene ring. The singlet at 11.7 ppm suggests the presence of one hydrogen atom of the OH group from the carboxylic acid group.

Based on the above observations, the given data suggests the following structure of the compound:

4-chlorophenyl acetic acid