Table 2.
[a] General conditions: Pyridinium (1.0 equiv), allyl sulfone (3.0 equiv), and 5 (1.5 equiv) in DMA (0.4 m) at 40 °C for 16 h. Yields are of isolated products after flash column chromatography. [b] Isolated after acetyl protection of the alcohol. [c] Reactions performed at 60 °C with 5 (2.5 equiv) and Et3N (3.0 equiv).