A compound is provided that is useful for, among other things, preparing water-soluble polymer derivatives bearing a terminal N-succinimidyl ester.
US9045494B2
申请人:——
公开号:US9045494B2
公开(公告)日:2015-06-02
Zirconocene-catalyzed epoxy ester - ortho ester rearrangement: A new method for the protection of polyfunctionalized carboxylic acids and the asymmetric synthesis of ortho esters
In situ prepared Cp2(Cl)Zr⊛ catalyzes the formation of ortho eśters from epoxy esters. Acid-sensitive α-amino and α-hydroxy acid derivatives are converted in high yield to 2,7,8-trioxabicyclo[3.2.1]octanes (ABO-esters) using this protocol. This strategy is complementary to the OBO-ester technology, and orthogonal methods for the deprotection of ABO- and OBO-esters have been developed. The syntheses