Titanium-mediated methylene transfer reactions on sugar esters, lactones, and uloses
作者:Mezher H. Ali、Peter M. Collins、W. George Overend
DOI:10.1016/0008-6215(90)80163-w
日期:1990.9
ketones into olefins and esters into vinyl ethers’. We now reportt its application to a variety of sugar derivatives that contain carbonyl and/or ester functions, with the aim of delineating the scope of the reaction with respect to blocking groups and the structure of the ketone, ester, or lactone. In order to simplify the procedure and increase the value of the method, the unpurified form of 2 was used
亚烷基钛1是一种通用的亚甲基化剂,易于从相当昂贵的Tebbe化合物2中衍生而来,已用于维蒂希型反应中,以将酮转化为烯烃和酯,转化为乙烯基醚。现在我们报道其在各种具有羰基和/或酯官能的糖衍生物中的应用,目的是描述关于保护基和酮,酯或内酯结构的反应范围。为了简化程序并增加方法的价值,使用了2的未纯化形式(请参见实验)。其他晶体[3]在某些醛糖内酯上使用了纯净的结晶Tebbe试剂,在可以进行比较的地方,发现了相似之处和不同之处。色谱分离后,使ulose 3(X = 0)和醛5(R = H)与2反应,得到 与9相比,它需要更小心的处理,因为它在硅胶上用中性洗脱液迅速水解,得到有用的酮5(R = Me)。&lactones 2,3,4,6-tetra-O-methyl-p-glucono-1,5-lactone(10,R = Me)和