用烯丙醇/ Ti(OR)4加热非对映异构纯N-酰基磺酰胺3或4,可有效产生阿磺胺1或2和烯丙基酯5。在威尔金森氏催化剂的存在下,在非碱性条件下将酯5水解,得到对映异构和非对映异构纯的羧酸7。因此,由N- [ N '-(Fmoc)氨基]酰基苏丹酰胺12制备了一系列[[芴-9-基)甲氧基]-羰基-(Fmoc)-保护的氨基酸14。
A newprotectinggroup, 1,2-dimethoxy-4,5-dimethylene, for acyclic amino acid derivatives could be introduced by N,N-dialkylation with 1,2-bis(bromomethyl)-4,5-dimethoxybenzene (1) and removed via amine de-alkylation with acyl chlorides. The method can be used with base-induced [2,3] and [1,2] Stevens rearrangement products.