Studies related to biological detoxification of kraft pulp mill effluent. V. The synthesis of 12‐ and 14‐chlorodehydroabietic acids and 12,14‐dichlorodehydroabietic acid, fish‐toxic diterpenes from kraft pulp mill effluent

An improved synthesis of the isomeric 12‐ and 14‐chlorodehydroabietic acids (3 and 2, respectively) and 12,14‐dichlorodehydroabietic acid (4) is described. The monochioro isomers were conveniently separated as the imidazole derivatives, and conversion of the latter to the free acids or their corresponding methyl esters could be achieved in high yield. Studies involving microbial degradation of 2–4 are underway.