C. Baldoli et al., COUMARIN AS DIPOLAROPHILE TOWARDS 3,5-DICHLORO-2,4,6-TRIMETHYLBENZONITRILE OXIDE, Journal of heterocyclic chemistry, 31(1), 1994, pp. 251-253
The reaction of coumarin with the title nitrile oxide gives a single r
egioisomer in high yield. This result is compared with the dipolarophi
lic behavior of cinnamic acid esters.