Calcium-Catalyzed, Dehydrative, Ring-Opening Cyclizations of Cyclopropyl Carbinols Derived from Donor–Acceptor Cyclopropanes
作者:Matthew J. Sandridge、Stefan France
DOI:10.1021/acs.orglett.6b01933
日期:2016.9.2
A calcium-catalyzed, dehydrative, ring-opening cyclization of (hetero)aryl cyclopropyl carbinols is reported. The cyclopropyl carbinols are prepared directly from the corresponding donor–acceptor (D–A) cyclopropanes. The calcium catalyst catalyzes the formation of putative (hetero)aryl cyclopropyl carbinyl cations that undergo ring-opening to allylcarbinyl cations. Subsequent intramolecular Friedel–Crafts
A novel ring-expansion of methyl (arylhydroxymethyl)cyclopropanecarboxylates 1 using Sc(OTf)3 or BF3·OEt2 afforded 1,2-dihydronaphthalene-3-carboxylic acid ester 2 in high to excellent yields. In t...