of the (-)-1-CO2Me salt (2 g) and tert-butyl carbamate (1.21 g) in CHzClz (10 mL) at 0'C was added dropwise diisopropylethylamine (0.86 mL). The resultant clear yellow solution was stirred for 5 min and then diluted with hexane (20 mL). Filtration then solvent removal left an oily solid which was heated in vacuo (50-60" C, 0.1 torr) to remove excess tert-butyl carbamate. Chromatography over silica gel (15% EtOAc in hexane) gave the complex as ...