Chemoselective Formation of 8,9‐Epoxy‐limonene

Abstract

We present here a synthetic path to produce, exclusively, 8,9-epoxy-limonene in 75% overall yields. We developed a three step synthetic route. First, the 1,2-double bond of limonene was protected by the formation of the bromo-methyl-ether by cohalogenation with NBS in MeOH. Then, this product was oxidized by m-chloro-perbenzoic acid to give the corresponding epoxides. Finally, the 1,2-double bond was restored by a reaction with NH₄Cl/Zn leading to 8,9-epoxy-limonene. The great advantage of this methodology is that the intermediate purification steps are not necessary.

Keywords:

• Epoxy
• limonene
• terpene

Acknowledgment

We thank CNPq and CAPES for financial support, and Claudia Moraes de Rezende for the mass analyses. We thank Flavia M. da Silva for helpful discussions.