[3 + 2] Cycloaddition Reactions of 4-Alkyl-3-hydroxy-2<i>H</i>-pyrazolo[4,3-<i>c</i>]iso- quinolinium Inner Salts
作者:Eifion D. Phillips、Simon C. Hirst、Matthew W. D. Perry、Jane Withnall
DOI:10.1021/jo034160f
日期:2003.10.1
dipolarophiles with 4-alkyl-3-hydroxy-2H-pyrazolo[4,3-c]isoquinolinium hydroxide inner salts results in [3 + 2] cycloaddition across positions 3a and 5 of the aromatic system to give the [3 + 2] cycloadducts in good yield. When the 4-alkyl substituent is a 2-acetate ester and the methylene group can be deprotonated, a second mode of [3 + 2] cycloaddition becomes available for the resulting anion (across