Chemistry and crystal structures of some constituents of zingiber cassumunar

Abstract

The novel aromatic compounds cis-3-(2′, 4′, 5′-trimethoxyphenyl)-4-[(E)-2"′, 4′, 5"′-trimethoxy-styryl]cyclohex-1-ene (1), cis-3-(3′, 4′-dimethoxyphenyl)-4-[(E)-3"′, 4′"-dimethoxystyryl] cyclohex-l-ene (2), a substance assigned the tentative structure cis-3-(3′, 4′-dimethoxyphenyl)-4-[(E)-2"′, 4′", 5′"-trimethoxystyryl]cyclohex-1-ene (3), (E)-4-(3′, 4′-dimethoxypheny1)but-3-en-1-ol (5), (E)-4-(3′, 4′-di-methoxypheny1)but-3-en-1-yl acetate (6), and 8-(3′, 4′-dimethoxypheny1)-2-methoxynaphtho-1, 4-quinone (7) have been isolated from the rhizomes of Zingiber cassurnunav Roxb. (Zingiberaceae). The crystal structures of the cyclohexene derivative (1) and the quinone (7) have been determined from X-ray diffractometer data at 295 K and refined by block diagonal least squares to residuals of 0.046 (2099 ′observed′ reflections) and 0.093 (1246), respectively. Crystals of compound (1) are triclinic, P ī, a 18.027(12), b 10.037(9), c 6.530(5) Å, α 84.22 (7), ß 81-87 (6), γ 85.72 (6)°, Z 2. Crystals of the quinone (7) are monoclinic, P 2 1 /a, a 22.89 (1), b 8.022 (5), c 8.458 (5) Å, ß 91.98 (5)°, Z 4. Although the latter crystal structure determination is imprecise, due largely to the very small size of the crystal available, the solution is unambiguous. A simple two-step synthesis of the quinone (7) has been achieved. © 1979 Australian Journal of Chemistry, All rights reserved.