A Common Conformation of Stabilized Triphenyl Phosphonium Ylidic Diesters with Bulky Alkoxy Groups

…, P Silva, MT Garland, A Shirazi, CA Bunton

Index: Castaneda, Fernando; Silva, Paul; Garland, M. Teresa; Shirazi, Ata; Bunton, Clifford A. Phosphorus, Sulfur and Silicon and the Related Elements, 2009 , vol. 184, # 1 p. 19 - 33

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Citation Number: 8

Abstract

The phosphonium ylidic diesters, methyl and ethyl isopropyl and, methyl and ethyl t-butyl triphenylphosphoranylidene malonates, 1a, b and 2a, b, respectively, have the syn-anti conformation in solution, as in the crystal, and the bulkier alkoxy group is oriented towards phosphorus. The 1 H NMR spectra show that in 1a, b, the isopropyl group is oriented towards the face of a phenyl group, consistent with π shielding in the 1 H signals, and ...