Constituents of the Zingiberaceae. XI. Structures of (+)-(1R,2S,3R,4S)-2-Benzoyloxymethylcyclohex-5-ene-1,2,3,4-tetrol 4-benzoate [(+)-Zeylenol] and (+)-(1R,2R,4R,5S,6R,7R)-4-Benzoyloxymethyl-3,8-dioxatricyclo-[5.1.0.02,4]octane-5,6-diol 5-Acetate 6-Benzoate (Boesenboxide) Isolated From a

A new Boesenbergia species ( Zingiberaceae ) has been found to contain (+)-(1R,2S,3R,4S)-2-benzoyloxymethylcyclohex-5-ene-1,2,3,4-tetrol 4-benzoate [(+)- zeylenol ] (2)and the crotepoxide -related substance, (+)-(1R,2R,4R,5S,6R,7R)-4-benzoyloxymethy1-3,8-Dioxatricyclo [5.1.0.02,4]octane-5,6-diol 5-acetate 6-benzoate ( boesenboxide ) (8). The structure (8) was determined by spectroscopic, chemical, and X-ray crystallographic studies. Boesenboxide forms monoclinic crystals P21, a 12.722(2), b 5.23O(l), c 16.139(3) Å, ß 106. 57(l)º; the crystal structure was refined to a residual of 0.029 for 1281 independent observed reflections.