| Summary: | 碩士 === 國立臺灣師範大學 === 化學研究所 === 92 === The lactone and lactam functionality are present in a large variety of natural products and biologically active compounds. For example, certain functionalized chiral γ-butyrolactones are sex attractant pheromones for several insect species and some are utilized as flavoring components. They also constitute a particularly useful class of synthons and chiral building blocks.
A new chiral auxiliary was prepared to react with acyl chloride, and get α,β-unsaturated carbonyl substrates of exo-10,10-diphenyl-2,10-camphanediol. The formation of lactones was carried out by reaction of various chiral auxiliary derivaties α,β-unsaturated olefins and ketones with samarium diiodide in the presence of t-BuOH at -78 ℃. The reaction was stirred at that temperature for 2hr, and then the reaction was gradually warmed to room temperature. Chiral butyrolactones were obtained in 40-70% yield and 70-80% ee, and chiral auxiliary was recovered at the same time. If the reaction was quenched at -78 ℃, we got reaction intermediates-tertiary alcohols with high diasteroselectivity(>88% de), and de value of the product was determined by crude 1H-NMR.
If oxime ethers was used instead of keones, the lactamization was proceeded at room temperature and the favored γ-butyrolactam was obtained with 55% ee. The absolute stereochemistry of lactam (129) was determined by single crystal X-ray analysis after reacting with camphorsulfonyl chloride and n-BuLi. The ee value of the product was determined by HPLC using chiral column(AS-H, AD).
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