EPOXIDATION OF PRIMARY AND SECONDARY ALKENYLAMMONIUM SALTS WITH DIMETHYLDIOXIRANE, METHYL(TRIFLUOROMETHYL) DIOXIRANE, AND M-CHLOROPERBENZOIC ACID - A GENERAL SYNTHETIC ROUTE TO EPOXYALKYLAMINES

Selective syn-epoxidation of C=C double bonds in primary and secondary alkenylammonium arenesulfonate salts 3H(+), to give the corresponding epoxyalkylammonium salts 4H(+), has been achieved by reaction with el ectrophilic O-transfer reagents such as m-CPBA, methyl(trifluoromethyl )dioxirane (TFDO), and dimethyldioxirane (DMDO). Epoxyalkylamines 4 ar e easily obtained in high yields from the corresponding epoxyalkylammo nium salts 4H(+) by simple deprotonation with sodium carbonate. The am monium group deactivates the C=C double bond, and hence the epoxidatio n rate is slower than in the case of simple olefins. II-Bonding intera ction between the ammonium group and the O-transfer reagent(m-CPBA and DMDO) in the transition state is claimed to account for the rate enha ncement and diastereoselectivity observed when the necessary conformat ional requirements are established. The allylic ammonium group is show n to be very efficient in directing the epoxidation with m-CPBA and DM DO on the syn-diastereoface.