ABSOLUTE-CONFIGURATION OF SEIRICUPROLIDE, A NEW PHYTOTOXIN FROM SEIRIDIUM-CUPRESSI

C14H20O5, M(r) = 268.31, monoclinic, P2(1), a = 5.0680 (5), b = 19.519 (2), c = 7.3968 (8) angstrom, beta = 106.03 (1)-degrees, V = 703.3 (1) angstrom 3, Z = 2, D(x) = 1.27 g cm-3, lambda(Cu K-alpha) = 1.54184 angstrom, mu = 7.55 cm-1, F(000) = 288, T = 298 K, R = 0.029 for 1286 reflections with F(o) greater-than-or-equal-to 4-sigma(F(o)). The absolute configurations of C4, C5, C6, C7 and C13 are R, S, R, S and S respectively. The C1-C2 and C8-C9 double bonds have E and Z configurations respectively. The determination of the absolute configuration of the title compound also allows that of its trans-bromohydrin derivative to be established.