Synthesis of 6H-dibenzo[b,d]pyran-6-ones via dienone-phenol rearrangements of spiro[2,5-cyclohexadiene-1,1′(3′H)-isobenzofuran]-3′-ones
作者:David J. Hart、Adrienne Kim、Ramanarayanan Krishnamurthy、Gregory H. Merriman、Anne-Marie Waltos
DOI:10.1016/s0040-4020(01)80487-7
日期:1992.1
A series of spiro[2,5-cyclohexadiene-1,1′(3′H)-isobenzofuran]-3′-ones were prepared from metalled benzamides and 4,4-dimethoxycyclohexadienone. Rearrangement of these spirodienones under a variety of conditions gave substituted 6H-dibenzo[b,d]pyran-6-ones. Rearrangements in aqueous sulfuric acid gave products of formal O-migration while rearrangements in trifluoroacetic anhydride-trifluoroacetic acid-sulfuric