(−)??Daucic Acid: Revision of Configuration, Synthesis, and Biosynthetic Implications

FW Lichtenthaler, K Nakamura…

Index: Lichtenthaler, Frieder W.; Nakamura, Katsumi; Klotz, Juergen Angewandte Chemie - International Edition, 2003 , vol. 42, # 47 p. 5838 - 5843

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Citation Number: 17

Abstract

The assignment of the configuration at C4 and C5 was less conclusive (Scheme 1), as it was inferred from low-resolution (60 MHz) 1H NMR spectroscopic data for dimethyl daucate (2) and its di-O-acetyl derivative, primarily from the coupling constants for 4-H and 5-H and comparison of these with analogous NMR spectroscopic data for certain 4, 5-unsaturated hexuronates,[4] which on close inspection prove unreliable.[5] Moreover, the half-chair ...