Synthesis of Optically Active [4.4] spiroketals and study of Carbon-Nitrogen and Carbon-Iodine Bonds Formation Mediated by Ceric Ammonium Nitrate

• Main Authors: Jr-Hang Chu, 朱志航
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/71570776417009881215

碩士 === 靜宜大學 === 應用化學系研究所 === 92 === Methyl 5-deoxy-2,3-O-isopropylidene-β-D-erythro-pent-4-enofuranoside 4 has been readily prepared from D-ribose. Employing cerium ammonium nitrate (CAN) to induce a series of 1,3-dicarbonyl compounds, such as: 2,4- pentanedione, ethyl acetoacetate, 1,3-cyclohexanedione, 5,5-dimethyl-1,3- cyclohexanedione, 1-benzoylacetone, dibenzoylmethane, 1,3-dimethyl barbituric acid and 4-hydroxycoumarin etc..., to generate corresponding the electron-poor radicals, which were proceeding [3+2] cycloaddition with 4 to obtain a series of the corresponding optically active dioxabicyclo[4.4] spiro ketals 5 with high stereoselectivity. In addition, CAN can also induced sodium azide and sodium iodide to produce azido and iodo radicals, which were proceeding the azdiohydroxylation and iodoalkoxylation with 4 in different solvents (CH3CN and small molecule of alcohols). Lactones 19 and 20 were obtained from 4 and 17 respectively by using CAN-sodium nitrite through the oxidative cleavage process.