J. Org. Chem. 1991,56,3137-3146
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oxygen, which was kept isotropic. The function minimized in the refinement was Cw(F,2 - F,2I2, where weights w were l/dL(F,2). Atomic form factors were from Doyle and T ~ r n e r , ’and, ~ for hydrogen, from Stewart, Davidson, and Simpson.“ In the final refmement cycle, all shifts were
