Cohalogenation of limonene, carvomenthene and related unsaturated monoterpenic alcohols

Abstract

Cohalogenation of (R)-limonene and (R)-carvomenthene with I2/H2O/Cu(OAc)2·H 2O in aqueous dioxane followed by base treatment produced stereospecifically the corresponding trans-epoxides. Same methodology of cohalogenation applied to related monoterpenic unsaturated alcohols produced pinol derivatives [from (5R)-cis-carveol and (S)-alpha-terpineol] or iodohydrins [from (S)-perillyl alcohol and (5R)-trans-carveol].

Keywords

• cyclisation, halohydrins
• terpenes and terpenoids
• electrophilic addition reaction