Approach to Merosesquiterpenes via Lewis Acid Catalyzed Nazarov-Type Cyclization: Total Synthesis of Akaol A
作者:Badrinath N. Kakde、Nivesh Kumar、Pradip Kumar Mondal、Alakesh Bisai
DOI:10.1021/acs.orglett.6b00446
日期:2016.4.15
asymmetric synthesis of carbotetracyclic core of merosesquiterpenes. The reaction works only in the presence of 2 mol % of Sn(OTf)2 and Bi(OTf)3 in dichloroethane under elevated temperature. The methodology offers the synthesis of a variety of enantioenriched arylvinylcarbinols from commercially available (3aR)-sclareolide 9 in six steps with an eventual concise totalsynthesis of marinesesquiterpene quinol
A very expedient and efficient new route toward taiwaniaquinoids, bearing the 4a-methyltetrahydrofluorene skeleton, is reported. Key steps are the intramolecular Friedel−Crafts alkylation of an aryldiene and the degradative oxidation of a methylenedioxy group; the latter process could also be utilized for building the 2-hydroxy-1,4-benzoquinone unit, which is frequently found in natural products. Utilizing