Treatment of readily available allene 1 with Cy2BH followed by addition of an aldehyde led to quaternary protected 2-amino-2-vinyl-1,3-diols in high yield and excellent stereochemical purity. The choice of benzoyl as N-protecting group is critical since the observed N- to O-Bz transfer during the process prevents later undesired isomerizations in the adducts and keeps all heteroatoms protected.
用Cy 2 BH处理易得的
丙二烯1,然后添加醛,可以高产率和优异的立体
化学纯度得到季保护的2-
氨基-2-
乙烯基-1,3
-二醇。选择苯甲酰基作为N-保护基是至关重要的,因为在该过程中观察到的N-向O -Bz的转移防止了加合物中后来不希望的异构化,并保持了所有杂原子的保护。