Use of epoxidation and epoxide opening reactions for the synthesis of highly functionalized 1-oxaspiro[4.5]decan-2-ones and related compounds

Epoxidation of ethyl 3-(6-hydroxycyclohex-1-en-1-yl)propanoate () provided the syn epoxide . By invoking chelation controlled epoxide opening the triol derivatives and or the spiro lactone could be obtained. Elimination of HBr from the bromides and produced the spiro cyclohexenones and . Epoxidation of the double bond occurred in a diastereoselective manner to give epoxides and , respectively. Treatment of the epoxide with LiBr/AcOH gave the bromo hydrin . In a ‘merry go round’ fashion was further functionalized on the cyclohexane ring by elimination, epoxidation, and epoxide opening resulting in the bromo hydrin . Other cyclohexane derivatives that were produced during these studies include the cyclohexenone and the cyclohexanediol . In addition, enolate azidation of the spiro lactone proceeded in a diastereoselective manner providing the α-azido lactone .