A novel water-soluble photochemical microreactor has been prepared. A perbutylated cyclodextrin bearing seven naphthalenesulfonate antenna chromophores (Bu-CD-N-7) displays improved solubilization of hydrophobic guests in comparison with the unbutylated material (CD-N-7). The photophysical properties of Bu-CD-N-7 are similar to those of the CD-N-7. The naphthyl chromophores of Bu-CD-N-7 were used to sensitize the photolysis of 9-anthrylmethyl pivalate (AP). Inclusion of AP in the cyclodextrin leads to the selective formation of one of the two possible coupling products.