TABLE 2.

Substrate scope.

All the reactions were conducted with 0.4 mmol of 1 (1.0 equiv.), 0.44 mmol of 2 (1.1 equiv.) and 1.2 mmol of base in MTBE (4.0 mL) at 40°C. Yields are those of the isolated products 3a–3n after column chromatography.