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organic compounds
The molecular structure of β-isopipitzol has been established as (1R,3R,6R,11R)-8-hydroxy-1,2,2,6-tetramethyltricyclo[5.2.2.03,11]undec-7-ene-9,10-dione, C15H20O3. The absolute configurations of the asymmetric centers at C3(R) and C11(R) were determined, based on the known configuration of the methyl group at C6, by means of X-ray crystallographic analysis and they confirm the structure previously assigned from chemical and spectroscopic evidence.