Abstract
Novel vinylborane-based trans-dihydroxyethylene equivalents were developed for the synthesis of trans-cyclohexenediol derivatives. The synthetic utility of the new dienophiles was demonstrated by their Diels-Alder reaction with simple dienes. One approach to a suitable trans-dihydroxyethylene equivalent was using a dienophile containing a dialkylbotyl group and a phenyldimethylsilyl group. traiis Dimethylphenylsilyl-9-vinyl-9-BBN dienophile was synthesized and reacted with aliphatic dienes. The cycloadducts were oxidized using various conditions, and the yields of the resulting silylcyclohexenols were reported. The hydroxyl group and the double bond of two silylcyclohexenols were protected by the Sharpless procedure. One of the resulting substituted cyclohexanes was then converted into the final polyoxygenated compound by Fleming's hydroxydesilylation method. The other approach to trans-dihydroxyethylene equivalents was using transdiborylethylenes as Diels-Alder dienophiles. Four trans-diborylethylenes were synthesized via a double tin-boron exchange between trans-bis(tributyltin)ethylene and the appropriate disubstituted bromoborane. The cycloadditions of these new dienophiles were explored.
Redman, Aniko Maria (1993). Vinylboranes as trans-dihydroxyethylene equivalents in Diels-Alder reactions. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -R318.