作者:Fridtjof Schröder、Gerhard Brunner、Laura Eberhard、Jürg Oetiker
DOI:10.1055/s-0029-1216999
日期:2009.11
from α-substituted (homo)allyl alcohols. In tandem reactions, cyclopropyl carbinols are obtained from allyloxylithium or -magnesium intermediates, generated in situ by alkylation of conjugated aldehydes, ketones, and esters as well as from allyl esters and carbonates or vinyloxiranes. [¹] cyclopropanation - Barbier conditions - Grignard addition - alkyllithium addition - dibromomethane
格氏试剂和二溴甲烷在环境温度下,在乙醚溶剂中有效地环丙酸烯丙基(和某些均烯丙基)镁和锂醇化物。在较高的Barbier条件下,将(均)烯丙基锂醇盐与镁和二溴甲烷直接环丙烷化。反应速率取决于(均)烯丙基醇化物的取代方式和取决于锂的抗衡离子,其效果最佳。从α-取代的(均)烯丙基醇获得良好至优异的顺选择性。在串联反应中,环丙基甲醇是从烯丙氧基锂或镁中间体获得的,该中间体是通过共轭醛,酮和酯的烷基化以及烯丙基酯和碳酸酯或乙烯基氧杂环戊烷而原位生成的。[ ¹] 环丙烷化-Barbier条件-Grignard加成-烷基锂加成-二溴甲烷