undergoes efficient, endo-selective and highly diastereoface controlled [4+2]-additions to cyclopentadiene, isoprene, (E)-piperylene and the 2-silyloxydienes 10 and 12. The resulting crystalline cycloadducts are smoothly reduced with LiAlH4 providing the recovered auxiliary and the corresponding enantiomerically pure alcohols.
R 2 AlCl配位的N-甲基
丙烯酰胺基1c经过高效,内选择性和高度非对映体控制的[4 + 2]加成到
环戊二烯,
异戊二烯,(E)-亚
戊二烯和2-甲
硅烷基氧二烯10和12上。用LiAlH 4平滑地还原所得的结晶环加合物,提供了回收的助剂和相应的对映体纯的醇。