Bicyclic- and Tricyclic-β-lactones via Organonucleophile-Promoted Bis-Cyclizations of Keto Acids: Enantioselective Synthesis of (+)-Dihydroplakevulin
摘要:
A highly diastereoselective, nucleophile-promoted bis-cyclization process, employing readily available and tractable keto acid substrates, is described. This methodology provides concise access to bicyclic- and tricyclic-beta-lactones bearing tertiary carbinol centers and quaternary carbons, greatly extending the scope of previous routes to bicyclic-beta-lactones from aldehyde acid substrates. The utility of the method was demonstrated by application to an enantioselective synthesis of (+)-dihydroplakevulin A. This and related processes may be revealing a subtle interplay between [2+2] cycloaddition and nucleophile-catalyzed aldol lactonization (NCAL) reaction manifolds.
申请人:National Institute of Advanced Industrial Science and Technology
公开号:EP1544190A1
公开(公告)日:2005-06-22
The present invention provides a safe, convenient and efficient method for producing carboxylic acid by a reaction of alicyclic alcohol with an aqueous hydrogen peroxide to thereby obtain carboxylic acid in high yield from alicyclic alcohol or alicyclic ketone under mild reaction conditions, wherein the reaction operation is simple and easy, a step for removing solvent after completion of the reaction is not necessary and influence and toxicity upon the environment and human body are markedly small. In order to provide it, an oily alicyclic alcohol is allowed to react with an aqueous hydrogen peroxide in the presence of a catalyst containing a metal compound belonging to Group 6 of the Periodic Table in a heterogeneous solution system.
The present invention provides a safe, convenient and efficient method for producing carboxylic acid by a reaction of alicyclic alcohol with an aqueous hydrogen peroxide to thereby obtain carboxylic acid in high yield from alicyclic alcohol or alicyclic ketone under mild reaction conditions, wherein the reaction operation is simple and easy, a step for removing solvent after completion of the reaction is not necessary and influence and toxicity upon the environment and human body are markedly small. In order to provide it, an oily alicyclic alcohol is allowed to react with an aqueous hydrogen peroxide in the presence of a catalyst containing a metal compound belonging to Group 6 of the Periodic Table in a heterogeneous solution system.