3-bromopropenyl esters

Catalytic enantioselective conjugate addition TABLE 13. The allylic substitution of 3-bromopropenyl esters using Cu/Taniaphos... 

Addition of 3-Bromopropenyl Esters Indium-mediated acyloxyaUylation of unprotected D-ribose, D-arabinose, D-lyjrose, and D-xylose were reported by Madsen et al. [50], in order to synthesize their corresponding heptosides. As an example, the treatment of D-ribose with 3-bromopropenyl acetate in ethanol at 50 °C in the presence of indium metal afforded the peracetylated polyol 85 in 82%. Only two out of the four possible diastereoisomers were observed with a 1.5 1 selectivity (Scheme 2.22). Deacetylation of the major D-isomer, isolated by flash chromatography, followed by ozonolysis gave the corresponding D-0ycero-D-manno-heptose 10. 

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