Regioselective synthesis of [6c,12b-cis]-6c,7,12,13-tetrahydro-1H-chromeno[3=B4, 4=B4: 4,5]pyrano[2,3-c]chromen-1-onesvia unusual [1, 6] Michael addition
作者:Krishna C. Majumdar、Pranab Chatterjee、Subrata Saha
DOI:10.1016/s0040-4039(98)01528-7
日期:1998.9
1-Aryloxymethylpyrano[2,3-c][1]benzopyran-5(3H)-ones(1a-f) on heating in N,N-diethyl-aniline suffered a [3s,3s] sigmatropic rearrangement followed by enolisation and an internal [1,6] Michael addition of the phenolic moiety to the diene-lactone moiety to give [6c,12b-cis]-6c,7,12b,13-tetrahydro-1H-chromenp[3=B4,4=B4: 4,5]pyrano[2,3-c]chromen-1-ones(2a-f) in 65–75% yield.
在N,N-二乙基苯胺中加热时,1-芳氧基甲基吡喃并[2,3- c ] [1]苯并吡喃-5(3 H)-ones (1a-f)发生[3s,3s]σ重排,随后烯醇化和酚部分向二烯-内酯部分的内部[1,6] Michael加成,得到[6c,12b-顺式] -6c,7,12b,13-四氢-1 H -chromenp [3 = B4,4 = B4:4,5]吡喃并[2,3 - c ] chromen-1-one (2a-f),产率65-75%。