The stereoselectivity of cycloaddition of sugar-containing substituted 1-(thiazol-2-yl)but-2-en-1-ones 1 and vinyl ethers was studied using the achiral vinyl ether/chiral catalyst as well as the chiral vinyl ether/achiral catalyst combinations. It has been shown that Eu(fod)3-catalyzed cycloaddition of oxadienes 1a-1e with the chiral vinyl ethers 9 and 10 affords stereoselectively almost pure cycloadducts 11a-11e and 12a-12e, respectively. The obtained cycloadducts are suitable precursors for the synthesis of α-C-(1→3)-disaccharides, containing 2-deoxy-arabino-hexopyranose moiety of D- or L-configuration.
糖基取代的1-(
噻唑-2-基)丁-2-
烯-1-
酮1和
乙烯醚的环加成立体选择性研究,使用了非手性
乙烯醚/手性
催化剂和手性
乙烯醚/非手性
催化剂组合。研究表明,欧洲
铕(fod)3催化的
氧代二
烯1a-1e与手性
乙烯醚9和10的环加成,分别选择性地得到了几乎纯的环加成产物11a-11e和12a-12e。所得的环加成产物是合成α-
C-(1→3)-二糖的合适前体,包含D或L构型的2-
脱氧-
阿拉伯-己糖基。