Methyl- and phenyl ketones 1a and 1b under microwave irradiation at 200 °C for five minutes afforded 2-methyl-5,6,7,8-tetrahydro-4H-cyclohepta[b]furan (2a) and 2-phenyl-5,6,7,8-tetrahydro -4H-cyclohepta[b]furan (2b) in 78% and 61% isolated yields, respectively (entries 1 and 2). Similarly, 1c and 1d afforded 2,3-dimethyl-5,6,7,8-tetrahydro-4H-cyclohepta[b]furan (2c) and 3-methyl-2-phenyl-5,6,7,8-tetrahydro-4H-cyclohepta[b]furan (2d) in 63% and 80% ...
