Structure of racemic isoptychanolide
Abstract
<h2>Acta Crystallographica Section C</h2><h3>Crystal Structure Communications</h3><h3>0108-2701</h3> <h2>research papers (organic compounds)</h2> Volume 43 Part 10 Pages 1964-1966 October 1987 <h2>Structure of racemic isoptychanolide</h2> J. H. Bieri, J. Huguet, M. Karpf and R. Prewo Acta Cryst. (1987). C43, 1964-1966 Structure of Racemic Isoptychanolide BY JOST H. BIERI, JOAN HUGUET,* MARTIN KARPFt AND ROLAND PREWO~ Organisch-Chemisches Institut der Universitdt Ziirich, Winterthurerstrasse 190, CH-8057 Ziirich, Switzerland (Received 4 February 1987; accepted 18 May 1987) Abstract. C15H2203, Mr=250.34, triclinic, P1, a =6.890(1), b=6.971 (1), c= 15.829 (2)/~, a= 87.15 (2), fl= 80.33 (2), y= 61.97 (1)°, V= 661.2 (2)/~3, Z = 2, Dx = 1.26 g cm-3, 2(Mo Ka) = 0-71069 A, /t = 0-80 cm-l, F(000) = 272, T~ 130 K, R = 0.057 for 6933 reflections. The configurations of all asymmetric carbon atoms except those in the oxirane ring are equal to those in ptychanolide. Introduction. Ptychanolide (1) is a natural product whose crystal structure has been published previously (Takeda, Naoki, Iwashita, Mizukawa, Hirose, Isida & Inoue, 1983). The diastereoisomer isoptychanolide (2) has been synthesized in racemic form (Huguet, Karpf & Dreiding, 1983; golaja, Huguet, Karpf & Dreiding, 1987). To establish the configuration at the spiro centre and at the oxirane