Phenylseleno Acrylate As A Novel Ethylene Equivalent for Diels-Alder Reactions And An ortho-Benzoquinone Cycloaddition Strategy Toward Morphine
In Chapter 1, a Diels-Alder cycloaddition strategy toward morphine utilizing highly reactive ortho-benzoquinones as dienophiles is reported. Various syntheses of the phenanthrene unit of morphine are accomplished. A highly functionalized cycloadduct was synthesized containing the entire framework of morphine including functionality for the final ring closures. A general synthesis of benzofurans via a conjugate addition to ortho-benzoquinones has also been developed and an intramolecular addition was investigated as a possible method to access the phenanthrene unit of morphine.
In Chapter 2, phenylseleno acrylate was investigated as a novel ethylene equivalent in the Diels-Alder reaction. Dienes were found to undergo the Diels-Alder reactoin with phenylseleno acrylate to provide phenylseleno ester cycloadducts in excellent yield and with high regioselectivity. The phenylseleno esters were cleaved via a radical reduction to yield the desired ethylene unit. The radical reduction of bicyclo[2.2.2.]octene and bicyclo[2.2.1]heptene cycloadducts produced several side products, which formed due to cyclopropylcarbinyl radical rearrangements.