Access to Fused Pyrroles from Cyclic 1,3-Dienyl Boronic Esters and Arylnitroso Compounds was written by Francois, Benjamin;Eberlin, Ludovic;Berree, Fabienne;Whiting, Andrew;Carboni, Bertrand. And the article was included in Journal of Organic Chemistry in 2020.Application of 13417-49-7 This article mentions the following:
Dienylboronates such as I were prepared by hydroboration of enynes with terminal alkyne moieties, by boron-Wittig reactions of bis(pinacolato)methane with enals, or by newly optimized tandem ring closing and olefin cross-metathesis and ring closing metathesis reactions of enynes or of triene II in the presence of the first- or second-generation Grubbs catalysts. Reaction of dienylboronates with aryl nitroso compounds RNO mediated by DBU in methanol yielded fused arylpyrroles such as III by a nitroso-Diels-Alder reaction followed by ring contraction. In the experiment, the researchers used many compounds, for example, 5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7Application of 13417-49-7).
5,6-Dihydro-2H-pyran-3-carbaldehyde (cas: 13417-49-7) belongs to tetrahydropyran derivatives. In organic synthesis, the 2-tetrahydropyranyl group is used as a protecting group for alcohols. 2-(Arylmethylene)cyclopropylcarbinols could be converted to the corresponding tetrahydropyrans stereoselectively in the presence of Brønsted acids under mild conditions. A plausible Prins-type reaction mechanism has been proposed.Application of 13417-49-7
Referemce:
Tetrahydropyran – Wikipedia,
Tetrahydropyran – an overview | ScienceDirect Topics