A versatile approach to (4S,5R)-4-benzyloxy-5-(alpha-hydroxyalkyl)-2-pyrrolidinones: Experimental evidences to the computational predictions

作者：Zhou Xiang; Zhang Pan Yuan; Ye Han Liang^*; Huang Pei Qiang

来源：Comptes Rendus Chimie, 2008, 11(1-2): 5-18.

DOI：10.1016/j.crci.2007.02.018

• dehydration
• enamides
• 2-pyrrolidinones
• epoxidation
• asymmetric synthesis
• stereoelectronic effects
• computations
• reaction mechanism

A versatile and highly diastereoselective four-step approach to (4S,5R)-N-benzyl-4-benzyloxy-5-(alpha-hydroxyalkyl)-2-pyrrolidinones 2, which starts from readily available (S)-N,O-dibenzylmalimide (5), is reported. Substituted 2-pyrrolidinones 2 are valuable building blocks for the asymmetric synthesis of hydroxylated pyrrolidine alkaloids. The method demonstrates high diastereoselectivities at the pyrrolidinone ring (C-4/C-5 trans), and low diastereoselectivities at the carbinolic center. Some interesting phenomena such as a remarkable difference in reactivity between the two diastercomeric N,O-acetals 6 towards the dehydration reactions, the isomerization of trans-diastereomers to cis-diastereomers (6), and the exclusive formation of (E)-enamides 8 were observed. These results provide experimental proofs to our previous computational predictions, or have been rationalized by calculations.

• 出版日期2008-2
• 单位厦门大学