Tandem Oxidation/Cyclization Reaction of 4-(Arylmethyl)oxy-2-diazobutyrate Derivatives
作者:Seiichi Nakamura、Hideaki Kondo、Shuji Nagano、Hiroyuki Yamakoshi
DOI:10.3987/com-18-s(t)67
日期:——
A tandem oxidation/cyclization reaction of gamma-(arylmethyl)oxy-alpha-diazobutyrate derivatives was investigated. While oxidative cleavage of the PMB ether was only observed upon treatment of an alpha-diazo-beta-ketoester with DDQ, oxidation of alpha-diazo esters with an sp(3) carbon at the beta-position was accompanied by intramolecular attack of the diazo carbon atom and expulsion of the nitrogen gas to give 2,3-dihydrofurans in modest to good yields when an electron-withdrawing group was substituted at the beta-position. Substrates bearing no electron-withdrawing beta-substituent were found to give rearranged products, albeit in modest yields. A benzofuran derivative could also be obtained, although a hydroquinone adduct was formed as a byproduct.