Takashi Matsumoto, Y. Takeda, S. Usui
Mar 15, 1996
Citations
0
Influential Citations
2
Citations
Journal
Chemical & Pharmaceutical Bulletin
Abstract
Methyl 13-acetyl-12-methoxy-8, 11, 13-podocarpatrien-18-oate, prepared from (+)-dehydroabietic acid, was converted into methyl 12-methoxy-7-oxo-5, 8, 11, 13-podocarpatetraen-18-oate (9) by a series of reactions : haloform reaction, decarboxylation, Jones oxidation, and dehydrogenation. Reduction of 9 with sodium borohydride, followed by treatment of the resulting 7-hydroxy compound with boron trifluoride etherate, afforded a rearranged ester, methyl 6-methoxy-1, 10-dimethyl-1, 2, 3, 4-tetrahydroanthracene-1-carboxylate. This was further converted into 6-methoxy-1, 1, 10-trimethyl-1, 2, 3, 4-tetrahydroanthracene (14) by means of the following reactions : lithium aluminum hydride reduction, pyridinium chlorochromate oxidation, and Huang-Minlon reduction. Compound 14 was finally converted into the desired orthoquinone (1) according to the procedure of Ghosh and Ghatak. The synthetic 1 was shown to be identical with natural umbrosone by spectral comparisons.