Furan and ethylene also undergo the Diels-Alder reaction. 6 In 1946 a patent by Thomas disclosed the condensation of anthracene with ethylene. 7 His only modification was to use a solvent with the high melting anthracene and he made no claim of condensing any substituted anthracene. Using essentially the same conditions as previous workers, it has now been found that 9-anthraldehyde, its methyl acetal, 9-aceto-, 9-acetoxy-, 9-cyano-, 9- ...
