Crystal and molecular structure of the germination stimulant strigol by X-ray analysis

Abstract

Single crystal X-ray analysis has defined the constitution and relative stereochemistry of strigol (1) a potent speed germination stimulant for witchweed (Striga lutea Lour.). Crystals are orthorhombic, space group P2₁2₁2₁ with Z= 4 in a unit cell of dimensions a= 9·15, b= 12·37, 15·37 Å. The crystal structure was elucidated from photographic data by direct phase-determining methods, and the molecular parameters refined by full-matrix least-squares calculations to R 0·082 over 1650 independent reflections.