Solid state kinetic resolution of β-lonone epoxide and dialkyl sulphoxides in the presence of optically active host compounds. The first enantioselective host–guest inclusion complexation in the solid state

Abstract

Kinetic resolution of (J-ionone epoxide and some dialkyl sulphoxides is achieved in the solid state in the presence of an optically active host compound, and is confirmed to proceed via a combination process of enantioselective inclusion complexation and selective oxidation in the solid state; enantioselective complexation in the solid state is also observed for oximes.

Optically Active Ionones and Derivatives: Preparation and Olfactory Properties

“…Epoxy-β-ionone 5 has been found in nature in tomatoes, [43] carrots, [44] raspberries, [45] black tea, [46] and tobacco, [47] and has been prepared in enantiomerically enriched forms both by resolution [40,48,49] and by enantioselective synthesis. [50] a) Resolution of the Racemate Optically active 5,6-epoxy-5,6-dihydro-β-ionones were prepared for the first time in 1981, by Eugster et al, [48] and their absolute configurations were determined from the starting materials, the optically active α-ionones (1).…”

“…[50] a) Resolution of the Racemate Optically active 5,6-epoxy-5,6-dihydro-β-ionones were prepared for the first time in 1981, by Eugster et al, [48] and their absolute configurations were determined from the starting materials, the optically active α-ionones (1). The (Ϫ)-and (ϩ)-4-hydroxy-β-ionones 35 were prepared [37] from the corresponding cis-epoxy-α-ionones, and submitted to Sharpless oxidation to provide cis-hydroxyoxirane 39 In 1990, a solid-state kinetic resolution of epoxy-β-ionone was reported by Toda et al [49] A 1:1 inclusion complex between racemic β-ionone and the optically active host (Ϫ)-trans-2,3-bis(hydroxydiphenylmethyl)-1,4-dioxaspiro [5.4]decane (42) was treated with 3-chloroperbenzoic acid. When equimolar amounts of peracid were employed, only racemic 5 was obtained, but in the presence of 2Ϫ3 equiv.…”

Formation of racemic compound crystals by mixing of two enantiomeric crystals in the solid state. Liquid transport of molecules from crystal to crystal

“…When powdered optically active host crystals are mixed with powdered racemic guest crystals, enantioselective molecular movement occurs and optical resolution of the racemic guest compound can be accomplished in the solid state. 6 By a combination of the enantioselective molecular movement in the solid state and fractional distillation, optical resolution can be achieved by distillation in the presence of an optically active host. 7 By mixing an optically active host and racemic guest in the solid state, one enantiomer of the guest forms an inclusion complex with the host by molecular movement and then the uncomplexed enantiomer distils at a relatively low temperature without degradation of the inclusion complex.…”

Optical resolutions by inclusion complexation with a chiral host compound

“…When a mixture of 10a, β-ionone (66) and m-chloroperbenzoic acid (MCPBA) is ground by mortar and pestle in the solid state, (+)-67 of 88% ee was obtained. 29 Mechanism of the kinetic resolution is shown below. Of course, all processes proceed in the solid state.…”

“…By the same procedure, (-)-27b of 30% ee, (+)-27c of 30% ee, and (-)-27d (ee was not determined) were obtained. 15 Reaction of rac-1-tert-butyl-3-chloroazetidin-2-one (28) with 25 gave the racphthalimide derivative (29). Optical resolution of rac-29 was accomplished efficiently by complexation with 15.…”