Table 2. Ylidene-Bridge Substituent Effects on YND–BME Fragmentation Kinetics.

^aOur previous report²³ provided k_obs values from linear fits of the curved integrated rate data for the fragmentation of the mixture of diastereomers taken to 90% completion. Herein, we report more representative k_obs values obtained from the reaction taken to 50% completion.

^bDiastereomeric ratios determined by ¹H NMR.

^cA complex mixture of eight diastereomers with overlapping ¹H NMR resonances was observed.