CESIUM FLUORIDE-MEDIATED CLAISEN REARRANGEMENTS OF PHENYL PROPARGYL ETHERS - SUBSTITUENT EFFECTS OF AN ORTHO-ALKOXY GROUP ON THE BENZENE-RING OR MODIFIED PROPARGYL RESIDUES

The expected 7-alkoxy-2-methylbenzo [b]furans were effectively given i n the CsF-mediated Claisen rearrangement of phenyl propargyl ethers wi th an o-alkoxy substituent on the benzene ring. On the other hand CsF did not affect the production of the corresponding benzo[b]furans when ethers, carrying a propargyl residue modified by either 1,1-dimethyl or 3-ethoxycarbonyl functions, were used as substrates in the rearrang ement.