Micelle-Mediated Trimerization of Ynals to Orthogonally Substituted 4H-Pyrans in Water: Downstream Rearrangement to Bioactive 2,8-dioxabicyclo[3.3.1]nona-3,6-diene Frameworks

An efficient trimerization of ynals to diversely substituted 4H-pyran constructs has been executed in water, under ambient conditions employing micellar catalysis. The method is in agreement with the ideas of green and sustainable chemistry. The locus of the micellar reaction site has been probed through proton NMR studies. A general acid-mediated downstream rearrangement of the derived 4H-pyrans to interesting 2,8-dioxabicyclo[3.3.1]nona-3,6-dienes has been observed.

Automated summary

An efficient trimerization of ynals to form diversely substituted 4H-pyran constructs has been achieved in water under ambient conditions using micellar catalysis. The reaction site of the micelles was probed through proton NMR studies, and a downstream acid-mediated rearrangement to 2,8-dioxabicyclo[3.3.1]nona-3,6-dienes was observed.