Functionalized diazo acetoacetates are prepared by an efficient Mukaiyama aldol reaction between 3-TBSO-2-diazo-3-butenoate with aldehydes and acetals under mild reaction conditions. A variety of substituted aldehydes and the corresponding acetals are both accessible in good to excellent yields through this methodology. MgI2 etherate (MgI2•(OEt2)n) is the preferred catalyst and, the addition proceeds
作者:Sandor Karady、Joseph S Amato、Robert A Reamer、Leonard M Weinstock
DOI:10.1016/0040-4039(96)01936-3
日期:1996.11
enol ether of α-diazoacetoacetate is used for the annelation of aromatic oxo compounds. The method involves condensation with the oxo compound in the presence of TiCl4 followed by rhodium octanoate-catalyzed ringclosure to afford furan derivatives by direct carbene isertion and β-naphthol esters by a Wolff rearrangement pathway.
Aldol-cyclization reaction sequence for the synthesis of tetrahydrofurans
作者:Michael A. Calter、Priyantha M. Sugathapala、Cheng Zhu
DOI:10.1016/s0040-4039(97)00766-1
日期:1997.6
The aldol reactions of alpha-diazo-beta-ketoesters with a variety of aldehydes produced adducts which underwent Rh(II)-catalyzed O-H insertion reaction to yield highly substituted tetrahydrofurans. Alkylation and decarboxylation of these tetrahydrofurans formed a wide variety of tetrahydrofuran structures. (C) 1997 Elsevier Science Ltd.