Solvent-dependent regioselectivity of hydrogen chloride-mediated ring opening of alkylidenecyclopropanone acetal
作者:Morifumi Fujita、Shinji Hanagiri、Tadashi Okuyama
DOI:10.1016/j.tetlet.2006.04.067
日期:2006.6
Ring opening reactions of 2-cyclohexylidene-3,3-dimethylcyclopropanone acetal (1) are readily induced by treatment of hydrogen chloride in various solvents. Bond cleavage takes place at the C1–C2 or C2–C3 bond, and the ratio of C1–C2/C2–C3 cleavages changes from >99/1 to <1/99 depending on the solvent. The two modes of bond cleavage must be initiated by protonations at the carbon–carbon double bond
通过在各种溶剂中处理氯化氢,容易诱发2-环己基-3,3-二甲基环丙烷缩醛(1)的开环反应。键裂解发生在C1-C2或C2-C3键处,取决于溶剂,C1-C2 / C2-C3裂解的比率从> 99/1变为<1/99。键断裂的两种模式必须分别通过碳-碳双键和乙缩醛氧的质子化作用引发。区域选择性可以通过确定碳的速率质子化和氧的平衡质子化来合理化。