Synthesis of optically active seven-membered 1,5-anhydrocarbasugars and 1,4,5-tribenzoyloxy-2-ethoxy cycloheptanes via [5+2] cycloaddition

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• 作者：Arun A. Yadav^a ; Prajakta S. Sarang^a ; Manishankar Sau^b ; Srinath Thirumalairajan^c ; ^&dagger ; ; ^sri@dal.ca ; Girish K. Trivedi^b ; ^{snehgkt@yahoo.com} ; Manikrao M. Salunkhe^d ; ^{mmsalunkhe@hotmail.com}
• 关键词：Carbasugar ; Cyclitol ; 3-Oxidopyrylium ylide ; Cycloaddition ; Stereocontrol
• 刊名：Tetrahedron Letters
• 出版年：2012
• 期刊代码：109_00404039
• 类别：ch
• 出版时间：11 July, 2012
• 卷：53
• 期：28
• 页码：3599-3602
• 文件大小：692 K

摘要

[5+2] Cycloaddition followed by asymmetric dihydroxylation procedure have been utilized to prepare novel cyclitols. Accordingly, rac-2伪-hydroxy-6伪-ethoxy-1,5-anhydro cyclohept-3-ene, dFont">10 derived from [5+2] cycloaddition of 3-oxidopyrylium ylide and vinyl ether has been recognized as a seven-membered carbasugar equivalent and elaborated to 1,4,5-tribenzoyloxy-2-ethoxy cycloheptanes through a flexible, regio- and stereoselective strategy involving Sharpless asymmetric dihydroxylation conditions to resolve the compounds obtained. The structures and relative configurations of newly synthesized (+)-2伪-acetoxy-6伪-ethoxy-3尾,4尾-dihydroxy-1,5-anhydro cycloheptane ((+)-dFont">12)); (鈭?-1尾,4尾,5尾-tribenzoyloxy-6伪-ethoxy cycloheptane ((鈭?-dFont">17) and (+)-1伪,4伪,5伪-tribenzoyloxy-6尾-ethoxy cycloheptane ((+)-dFont">17) are unambiguously established by single crystal X-ray analysis and duly supported by ¹H and ¹³C NMR spectroscopy data.