| Summary: | Two approaches to the synthesis of <i>para</i>-menthene epoxide ((1<i>S</i>,5<i>S</i>,6<i>R</i>)<i>-</i><b>4</b>) are developed. The first approach includes a reaction between chlorohydrin <b>7</b> and NaH in THF. The second involves the formation of epoxide in the reaction of corresponding diacetate <b>6</b> with sodium <i>tert</i>-butoxide. One possible mechanism of this reaction is proposed to explain unexpected outcomes in the regio- and stereospecificity of epoxide (1<i>S</i>,5<i>S</i>,6<i>R</i>)<i>-</i><b>4</b> formation. The epoxide ring in (1<i>S</i>,5<i>S</i>,6<i>R</i>)<i>-</i><b>4</b> is then opened by various <i>S</i>- and <i>O</i>-nucleophiles. This series of reactions allows for the stereoselective synthesis of diverse derivatives of the monoterpenoid Prottremine <b>1</b>, a compound known for its antiparkinsonian activity, including promising antiparkinsonian properties.
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