Regioselective Synthesis of Bioactive Polyheterocycles: Sequential [3, 3] Sigmatropic Rearrangements of 6-(4-Aryloxybut-2-yn-1-yloxy)[1]Benzopyran-2-Ones
作者:K. C. Majumdar、P. Chatterjee
DOI:10.1080/00397919808004939
日期:1998.10
7a-Methyl-13,13a-dihydro-7aH-furo[3,2-c : 5,4-f']bis-[1]benzopyran-3-ones (4a-d) are regioselectively synthesised in 65-75% yields by the sequential rearrangements of 6-(4-aryloxybut-2-yn-1-yloxy)[1]benzopyran-2-ones (3a-d) in refluxing N,N-diethylaniline (15 h). However, addition of toluene-4-sulphonic acid in the reaction mixture improved the yield (80-85%) and reduced the reaction time (10 h).