Development of the juliá asymmetric epoxidation reaction. Part 1. Application of the oxidation to enones other than chalcones

Epoxidation of (E,E)‐Cinnamylideneacetophenones with Hydrogen Peroxide and Iodosylbenzene with Salen‐MnIII as the Catalyst

“…Studies on the asymmetric epoxidation reaction developed by Juliá and Colonna35 showed that a wide variety of substrates, such as enones, enediones and unsaturated keto esters, could be oxidized into optically active epoxides with basic hydrogen peroxide and poly(amino acids) 36–38. Later on, the same group39,40 reported the use of a non‐aqueous variant of the Juliá–Colonna reaction for the epoxidation of dienones and trienones, which includes the synthesis of α,β‐monoepoxides of ketones related to cinnamylideneacetophenones.…”

Asymmetric processes

“…101, 102 The epoxides 69 are formed in high yields and ees, and the poly(leucine) catalyst is commercially available, or easily prepared in both -and -forms.…”

Oxidation

“…A prominent example is the well-known Weitz-Scheffer epoxidation using alkaline hydrogen peroxide or hydroperoxides in the presence of base. In the course of exploration of the scope of the Juliá -Colonna procedure many enone substrates were successfully epoxidized by use of the original three-phase conditions ( acids affords the product epoxide of opposite absolute configuration [71]. In the (metal-based) approaches of Enders [56,57], Jackson [58,59], and Shibasaki [60,61] enantiomeric excesses > 90% have been achieved for a variety of substrate classes.…”

“…More complex structures and their epoxidation products are shown in Scheme 10.9 [71,82,83]. More complex structures and their epoxidation products are shown in Scheme 10.9 [71,82,83].…”