the present invention is directed to the synthesis of 2 - chloro - cis -- 9a -] dibenzofuran - 4 - carboxylic acid by an intramolecular heck stereospecific synthesis substantially free of undesirable 8 - chloro - 2 , 6 - methano - 2h - 3 , 4 , 5 , 6 - tetrahydro - 1 - benzoxocin - 10 - carboxylic .