Stereoselective Preparation of Optically Active 6-Deoxy-6, 6, 6-trifluorohexopyranoses
Stereoselective Preparation of Optically Active 6-Deoxy-6, 6, 6-trifluorohexopyranoses
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光学活性6-脱氧-6,6,6-三氟吡喃糖的立体选择性制备
DOI：
10.5059/yukigoseikyokaishi.52.734
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
T. Kitazume
中科院分区：
文献类型：
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作者：
T. Yamazaki;K. Mizutani;T. Kitazume
虽然6-脱氧-6，6，6-三氟糖被认为是天然抗生素中可能的生物活性物质，但在我们的项目开始时，甚至没有关于其制备的报道。然后，作者计划通过具有三氟甲基部分的呋喃醇的酶促光学拆分，然后过酸氧化产生2-丁烯内酯，以光学纯的形式合成这类糖。在我们的研究过程中，发现当采用在呋喃环中具有三甲基甲硅烷基或叔丁基二甲基甲硅烷基部分的底物时，这种分辨率是高效的，以良好的产率提供几乎光学纯的材料。首次考虑了将上述丁烯内酯或其氢化衍生物丁内酯转化为相应的六元环结构的吡喃己糖需要复杂地使用保护基。然而，这一问题被解决的顺序1，2-硅烷基迁移-环扩展，这是新颖的装置，考虑到性质的乳醇的发展。这一独特的反应得到了MOPAC（AM 1）半经验分子轨道计算的定性支持。
Although 6-deoxy-6, 6, 6-trifluorosugars are considered as possible biologically active materials incorporated into naturally occurring antibiotics, there has been no report even on their preparation when our project has started. Then, the authors have planned to synthesize this class of sugars in an optically pure form via enzymatic optical resolution of furanols with a trifluoromethyl moiety, followed by peracid oxidation leading to 2-butenolides. During our study, this resolution was found to be highly efficient when substrates with trimethylsilyl or t-butyldimethylsilyl moieties in the furan ring were employed, furnishing almost optically pure materials in good yields. It was considered for the first moment that the complicated usage of protective groups would be required for the transformation of the above butenolides or their hydrogenated derivatives, butyrolactones, into the corresponding hexopyranoses with a 6-membered ring structure. However, this problem was solved by the development of the sequential 1, 2-silyl migration-ring expansion, which was novelly deviced by the consideration of the characteristics of lactols. This unique reaction was qualitatively supported by semiempirical molecular orbital calculations by MOPAC (AM 1).