Synthetic studies towards oxylipins: total synthesis of Constanolactones A and B

The sequential addition of functionalised chains onto a 1,2-diformylcyclopropane synthon provides rapid access to cyclopropyl oxylipins, as demonstrated here by the total synthesis of Constanolactones A-B. These eicosanoids of marine origin have been prepared in five steps, first by the regioselective gamma-addition of 1-trialkylsilyloxy-1-ethoxybutadiene to (1S,2S)-1-formyl-2-(thexyldimethylsilyloxymethyl)cyclopropane, then, after functional group modifications, addition of a (1E,3S,5Z)-3-hydroxyundeca-1,5-dienyl organometallic. (C) 2000 Elsevier Science Ltd. All rights reserved.