Zinc Iodide Mediated Cyclization of ω-Silylalkynyl-α-cyanoketones—A Facile Methylenecyclopentane and Methylenecyclohexane Annulation Process

• Main Authors: Cheng-Feng Liao, 廖正峰
• Other Authors: Hsing-Jang Liu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/00040122530766041403

碩士 === 國立清華大學 === 化學系 === 94 === Construction of a methylenecyclopentane ring is an important issue in synthesis of natural products. This thesis delineated a newly developed process toward highly functionalized methylenecyclopentanes. Recently, we developed an efficient methylenecyclopentane annulation process to construct the functionalized methylenecyclopentanes. The efficient methylenecyclopentane annulation involves a convenient 1,4-addition of (4-buty-1-nyl)trimethylsilane magnesium chloride to 2-cyano-2-cycloalkenone 1 and following a zinc iodide promoted annulation of the resulting bicyclic product 3. We also developed the process toward methylenecyclohexane annulation via compound 4 under the same condition. This annulation process can be accomplished in mild condition and the yield is high. The utility of the functionalized methylenecyclopentane annulation was also be studied.