Metal Trifluoromethanesulfonate-Catalyzed Regioselective Reductive Ring Opening of Benzylidene Acetals
作者:Chi-Rung Shie、Zheng-Hao Tzeng、Cheng-Chung Wang、Shang-Cheng Hung
DOI:10.1002/jccs.200900076
日期:2009.6
study of various metal trifluoromethanesulfonates as efficient catalysts in the regioselective reductive ring opening of benzylidene acetals is described, including the effects of solvents, reducing agents, and temperature. These catalysts are found to be effective in cleaving the 4,6‐O‐acetal rings of hexopyranosides at either O4 or O6, respectively. When used in conjunction with a 1 M solution of
系统地研究了各种金属三氟甲磺酸盐作为亚苄基乙缩醛的区域选择性还原开环中的有效催化剂,包括溶剂,还原剂和温度的影响。发现这些催化剂可有效裂解六吡喃糖苷在O4或O6处的4,6- O-乙缩醛环。与1M BH 3溶液一起使用时·THF中的THF无需额外添加任何溶剂,它会影响O6位置的环裂变以生成相应的伯醇,而在乙腈中以二甲基乙基硅烷作为还原剂存在会导致O4的开环,从而导致生成仲羟基衍生物高选择性和高收率。这些方法可以应用于包含各种官能团的多种基材。