壹、對掌α,β-不飽和烯類與?氧類偶極化合物之非鏡像[3+2]環化加成反應 貳、以樟腦架構為主的新對掌螯合劑之設計與合成

藍錦全(Jung Chaing Lain)

指導教授 ： 陳焜銘

國立臺灣師範大學/理學院/化學系/碩士(2000年)

摘要

無資料

關鍵字

樟腦

並列摘要

Abstract
Two camphor-derived chiral auxiliaries exo-10,10-diphenyl-2,10-camphandiol 91 and camphor pyrazolidinone 92 were prepared and used for asymmetric [3+2] nitrile oxide cycloaddition. exo-10,10-Diphenyl-2,10-camphandiol 91 with 1,3-diol functional groups can be prepared from the known (R)-ketopinic acid 93 in 3 steps with a total of 64% yield. Cycloaddition of the derived chiral acryloy ester 99 with various nitrile oxides in CH2Cl2 provided a disappointly low diastereomeric ratio (56% de) in a total of 85% yield. The second structural unique camphor pyrazolidinone 92 was prepared from the known (R)-ketopinic acid 93 in 3 steps in a total of 74% yield. The absolute stereochemistry of the chiral auxiliary was assigned unambiguously by X-ray crystallographic analysis. Cycloaddition of the derived N-enoyl pyrazolidinones 100 with various nitrile oxides in CH2Cl2 provided isoxazolines with high diastereomeric ratio in a total of 90% yield. The diastereomeric excess was determined by 1H-NMR anslysis on the relevant signals and the diastereomeric excess was determined to be higher than 99%. The chiral auxiliary can be easily cleavaged by treatment with L-selectride in THF at –78 oC to provide essentially optical pure 2-isoxazoline. The chiral auxiliary was recovered in good material yield. Excellent enantiomeric excess was obtained by means of optical rotation comparison.
The second part of this thesis focus on the design and synthesis of new chiral ligands. (3-Oxo-camphorsulfonyl)imine 207 is prepared from the known (R)-camphorsulfonic acid 204 in 2 steps in a total of 51% yield. Camphorquinone 221 is prepared from (R)-camphor 220. Treatment of camphorquinone 221 or 3-oxo-camphorsulfonylimine 207 with amine or diamine derivatives under acidic condition provide the desired ligands. The structures of the camphor-based ligands were assigned by 1H-NMR, 13C-NMR and the absolute stereochemistry was further confirmed unambiguously by X-ray crystallographic analyses.

並列關鍵字

camphor ； nitrile oxide

參考文獻

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