The crystal and molecular structure of spiro[1-(S)-Br-3-(S)-H-4-(R)-l-(1 'R,2 ' S,5 ' R)-menthyloxy-5-oxo-6-oxa-bicyclo [3.1.0]hexane-2,3 '-(R)-(4 '-(R)-diphenylmethoxy-5 '-l-(1 ' R,2 ' S,5 ' R)-menthyloxy-butyrolactone)]

Crystal structure of C41H53O7Br has been determined by single-crystal X-ray diffraction. The compound crystalline in the orthorhombic space group P2(1 )2(1)2(1), with a = 11.264(2), b = 12.058(2), c = 29.337(6) Angstrom, Z = 4 . The bond angles of cyclopropane moiety in the molecule are approximate to 60 degrees and agree with theoretic values of the internal angles in a cyc lopropane, and two chiral menthyloxy groups are located above and under the whole chiral molecule, respectively. The configuration of the pentacyclic lactone is shown as envelope form.