6H-Dibenzo[b,d]pyran-6-one is one of the basic structure included in the compounds such as a natural product, drug medicine. It is reported that analogues having 6H-dibenzo[b,d]pyran-6-ones show various kinds of bioactivity. We reported a palladium-mediated intramolecular aryl-aryl coupling reaction for the effective construction of 6H-dibenzo[b,d]pyran-6-ones. Two kinds of regioisomers having the aryl-aryl linkage to ortho or para position of substituent (R) are isolated in the case of substrate with substituent (R) on the phenoxy part. In this time, we investigate this coupling reaction, and we consider that reaction system and the substituent of the substrate influence to regioselectivity.
