Abstract:

The (-)-(4R,10R,9S,5R)-7,13-abietadien-18-oic acid with 99.15% high purity was prepared in 74.2% yield by a isomerization, crystallization separation method with the acid as catalyst. Its structure was determined by MS, ¹HNMR, ¹³CNMR, IR spectral methods and single-crystal X-ray diffraction analysis. The data of abietic acid by single-crystal X-ray diffraction analysis was in accordance with that having obtained from Pinus elliottii rosin and Pinus massoniana rosin directly. Crystals are monoclinic, space group P₂₁ and their absolute configuation from rearrangement are the same as natural abietic acid. In the crystal structure of abietic acid, the carboxyls of two abietic acid molecules generated hydrogen bonds, which is the main reason for high purity crystal.

Key words: abietic acid, isomerization, single-crystal X-ray diffraction, structure, pine gum