Epoxides, vinyl alcohol protection

Takahashi et al. also reported a route to muconin. Their synthesis adopted Keinan et al. s strategy to construct the stereochemistries by Sharpless AD and AE upon multiple olefin containing fatty acid (Scheme 10-35). The di-olefin 214 was subject to Sharpless AD conditions and then treated with acid, yielding a THP-containing diol. This diol was further protected as acetonide 215. The reversion of stereochemistry of alcohol 215 was achieved by Dess-Marlin oxidation and Zn(BH4)2 reduction. Williamson etherification of tosylate 216 and epoxide formation afforded tri-ring intermediate 217. Opening with acetylene, 217 was converted into the terminal alkyne 218, which was coupled with vinyl iodide to finally give muconin. 

Compound (E) was prepared from levoglucosan and, after transformation into its tosylate and the corresponding epoxide, was opened with DMSO anion to give a dimethylated alcohol after desulfurization. The alcohol was then transformed into the corresponding lactol. Reduction of the lactol to the expected triol followed by a tandem protection-oxidation process afforded an aldehyde, which was then coupled with the vinyllithium reagent generated from the corresponding vinyl iodide [190]. The major diastereoisomer was transformed, after a... 

Terminal alkenes, primary aUylic alcohols, esters, aUyl boronate esters, aUyl halides, styrenes (without large orf/ro-substituents), aUyl phosphonates, aUyl sUanes, aUyl phosphane oxides, aUyl sulfides, protected aUyl amines Styrenes (with large ert/jo-substituents), acrylates, acrylamides, acrylic acid, acrolein, vinyl ketones, unprotected tertiary aUyfic alcohols, vinyl epoxides, secondary aUyhc alcohols, perfluoroalkyl alkenes... 

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