락탐화합물의 고리확장연구 : 입체선택성과 Mechanism에 관한 연구
vi, 58 p.
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The ring expansion chemistry is one of the most important methods to prepare five- and six-membered hetero cyclic compounds. we have studied about γ-lactam ring expansion with steroselectivity from β-lactam derivative. To do this chemistry, proton of N-benzyl group in β-lactam derivatives is eliminated by LDA and make carbanion. This anion make unstable 4-membered lactam intermediate, and then the ring is opened by homo cleavage or hetero cleavage for releasing ring strain, followed by recyclization to insert one carbon to make γ-lactam ring with stereoselectivity in β-, γ- positions.