Regio- and stereo-selective synthesis of carbohydrate isoxazolidines by 1,3-dipolar cycloaddition of nitrones to 5,6-di-deoxy-1,2- O -isopropylidene-α- d - xylo -hex-5-enofuranose
作者:Usama A.R. Al-Timari、L̆ubor Fis̆era、Igor Goljer、Peter Ertl
DOI:10.1016/0008-6215(92)84054-v
日期:1992.3
The synthesis of 2-phenyl-3-aryl and 2-phenyl-3-aroyl derivatives 5-(1,2-O-isopropylidene-alpha-D-xylo-tetrofuranos-4-yl)isoxazolidi ne (3) from nitrones and 5,6-dideoxy-1,2-O-isopropylidene-alpha-D-xylo-hex-5- enofuranose (1) is described. The 1,3-dipolar cycloaddition reactions given mainly anti adducts 3 and 4 (greater than or equal to 95% pi-facial stereoselectivity). The cycloadducts 3 with H-3
由硝酮和苯甲基合成3-苯基-2-芳基和2-苯基-3-芳基衍生物5-(1,2-O-异亚丙基-α-D-二甲苯基-对呋喃基-4-基)异恶唑二烯(3)描述了5,6-二脱氧-1,2-O-异亚丙基-α-D-二甲苯基-己-5--5-呋喃呋喃糖。1,3-偶极环加成反应主要给出抗加合物3和4(大于或等于95%的pi-面立体选择性)。具有H-3,5顺式的环加合物3在反式非对映异构体4上排他地或优先形成。