Stereoselective synthesis of flavonoids. Part 4. Trans- and cis-dihydroflavonols
作者:Hendrik van Rensburg、Pieter S. van Heerden、Barend C.B. Bezuidenhoudt、Daneel Ferreira
DOI:10.1016/s0040-4020(97)00916-2
日期:1997.10
Epoxidation of a series of poly-oxygenated chalcones with H2O2 in the presence of poly-α-aminoacids yielded chiral aromatic oxygenated oxiranes in moderate to high optical yields. Lewis acid-catalysed phenylmethanethiol ringopening of the epoxide functionality and subsequent formation of the pyranone heterocycle, afforded trans- and cis-dihydroflavonols in moderate to high enantiomeric excess and yield
在聚-α-氨基酸的存在下,用H 2 O 2对一系列多加氧的查耳酮进行环氧化,以中等至高的光学收率得到了手性芳族加氧的环氧乙烷。路易斯酸催化的苯基甲的环氧化物官能团和吡喃酮杂环的随后形成,得到ringopening反式-和CIS在中度至高度对映体过量和产量-dihydroflavonols。