Ynolide strategies

This ynolide strategy was applied to the synthesis of the raacrolide aigialomycin D by Geng and Danishefsky [66]. 

If triple bonds are implemented in cycloadditions with six-membered cychc dienes, an irreversible release of an alkene moiety claims for another type of arene synthesis. Driven by the search for novel antitumor agents, Danishefsky exploited this strategy during the synthesis of cycloproparadicicol [13]. The dimedone-derived electron-rich diene 22 cycloadds to the activated triple bond of the compound termed ynolide 23 at elevated temperatures, whereupon a concomitant extrusion of isobutene uncovers the aromatic core (Scheme 6.5). The trimethylsilyl (TMS) ether groups get cleaved during chromatography, furnishing the precursor 25 of cycloproparadicicol in 75% yield. 

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