A multi-linear-regression analysis using the Kamlet-Abboud-Taft (KAT) solvatochromic parameters in order to elucidate and quantify the solvent effects on the17O chemical shifts of (E)-1,1,1-trichloro-4-methoxy-3-penten-2-one (1) and (E)-1,1,1-trichloro-4-methoxy-3-methyl-3-buten-2-one (2) are reported. The chemical shifts of carbonyl group of the two molecules show similar dependencies (in ppm) on the solvent polarity-polarizability (-17*, -15*) and the solvent hydrogen-bond-donor (HBD) acidities (-7α, -6α). The influence of the solvent hydrogen-bond-acceptor (HBA) basicities is significant for compound 1 (3β) and small for compound 2 (0.7β).