THE CRYSTAL STRUCTURE OF TRIPTOPHENOLID REVISITED

Triptophenolide, C₂₀H₂₄O₃, has been assigned two isomeric structures. DF Yu etal reported the X-ray analytical structure Ⅱ in 1990⁽²⁾. In 1982, however, FX Deng et al had alreadyreported the spectrometric assignment of structure Ⅰ⁽¹⁾. Now, we report again the single crystal analys-is of triptophenolide (Ⅰ). The crystal belongs to space group P₂₁₂₁₂₁ of orthorhombic system, with a=7. 270(6), b=12. 509(8), c=36.20(1)A, Z=8. The structure was solved by direct method andrefined by the full-matrix least-square method to a final R factor 0. 055, based on 2322 intensitieswith I≥3σ(I). It is highly probable that the result of DF Yu was in error with only 1292 available in-tensities.