The asymmetric α-allylation of 3-pentanone using several different N-amino cyclic carbamate (ACC) auxiliaries is described. The level of asymmetric induction was found to range from er = 93:7 to er = 99:1. The factors that lead to compromised selectivity for the various auxiliaries have been determined. Significantly, we have established that using the easily accessible and inexpensive valine-derived
描述了使用几种不同的N-
氨基环状
氨基甲酸酯(ACC)助剂的
3-戊酮的不对称α-烯丙基化。发现不对称感应的
水平为er = 93:7至er = 99:1。已经确定了导致各种助剂选择性受损的因素。重要的是,我们已经确定,使用容易获得且价格便宜的缬
氨酸衍生的ACC辅助剂,可以获得合成上有用的不对称诱导
水平(er = 96:4)。