New annulations via platinum-catalyzed enyne cyclization and cyclopropane cleavage.
[reaction: see text] Oxidative ring opening of 3-oxabicyclo[4.1.0]hept-4-enes, formed by the intramolecular Pt(II)-catalyzed cyclopropanation of enol ethers by alkynes, gives oxepane derivatives. Alternatively, the acid-catalyzed opening of the cyclopropane ring leads to dihydrobenzofurans or 3,4-dihydro-2H-chromenes.
Institute of Chemical Research of Catalonia, 43007 Tarragona, Spain.
Cristina
C
Nevado
Catalina
C
Ferrer
Antonio M
AM
Echavarren