One-Step Conversion of Aldehydes to Oxazolines and 5,6-Dihydro-4H-1,3-oxazines Using 1,2- and 1,3-Azido Alcohols
摘要:
The reactions of 1,2- and 1,3-hydroxy azides with aldehydes under acidic conditions were examined. A variety of Lewis acids were examined, of which BF3 . OEt(2) was found the most convenient. Trimethylsilyl ether derivatives of the alcohols could also be reacted using trimethylsilyl triflate as the promoter. Twenty-five examples that proceed in moderate to quantitative yields are reported.
One-Step Conversion of Aldehydes to Oxazolines and 5,6-Dihydro-4<i>H</i>-1,3-oxazines Using 1,2- and 1,3-Azido Alcohols
作者:Jennifer G. Badiang、Jeffrey Aubé
DOI:10.1021/jo9521256
日期:1996.1.1
The reactions of 1,2- and 1,3-hydroxy azides with aldehydes under acidic conditions were examined. A variety of Lewis acids were examined, of which BF3 . OEt(2) was found the most convenient. Trimethylsilyl ether derivatives of the alcohols could also be reacted using trimethylsilyl triflate as the promoter. Twenty-five examples that proceed in moderate to quantitative yields are reported.
Ring expansion by in situ tethering of hydroxy azides to ketones: The boyer reaction
作者:Vijaya Gracias、Kristine E. Frank、Gregory L. Milligan、Jeffrey Aubé
DOI:10.1016/s0040-4020(97)01012-0
日期:1997.12
under the action of protic or Lewis acids such as BF3·OEt2. The reaction appears to succeed due to the initial formation of a hemiketal, which then renders the attack of azide on an oxoniumion intramolecular. The scope of this reaction vis à vis ketone and hydroxyalkyl azide structure is discussed.