1, R-CH, 2, R: CH, CH, present is indicated by the essential identity of room temperature spectra to those at-90 OC. At this temperature, rotation about amide and thioamide bonds should be slow on the NMR time scale.'* Addition of KSCN to solutions of 1 at-90 OC resulted in the appearance of new signals in the'H NMR spectra at 6 2.58 and 2.23, which must be due to the thioacetyl and acetyl groups, respectively, in (Z, Z)-l. M+. Since the ...
