Episulphides, oxidation

Enantiomers, preferential crystallization of 59 Endo selectivity 798 Ene reactions 808, 809 Enones, synthesis of 732 Enthalpies of formation 102, 103 Enynes, synthesis of 956 Enzymatic kinetic resolution 829 Epimerization 399 Episulphides, oxidation of 237 Episulphones 650, 775 Episulphoxides, photolysis of 742 a,/J-Epoxysulphones reactions of 811, 812 rearrangement of 685 synthesis of 612 / ,y-Epoxysulphones 781 y,<5-Epoxysulphones 627, 628 Epoxysulphoxides reactions of 613 rearrangement of 744 synthesis of 327, 612 Erythronolides 831... 

The oxidation of 3-substituted 2a,5a-episulphides with m-chloroperbenzoic acid gives anti-sulphoxides (c.g. 478) (cf. the formation of s> n- or anti-sulphoxides from the unsubstituted episulphide ). Reaction of the 3/ -bromo-sulphoxide (478) with phenyl-lithium gives the 2,4-diene (480), probably via an unstable 5a-phenylsulphinyl-2-ene (479), which can undergo a normal sy -elimination. ... 

A report has appeared on the oxidation of 3-substituted 5a-cholestan-2a,5-episulphides with m-chloroperbenzoic acid, thus affording the corresponding awfi-sulphoxides. ... 

Alkene Synthesis.—The alkene synthesis by two-fold extrusion processes (see Vol. 3, pp. 246, 693) is discussed in Chapter 2 of this Volume (p. 89). The addition of diazo-compounds to suitable thiones provides an alternative route to A -l,3,4-thiadiazolines, which give episulphides on pyrolysis and hence alkenes on further reaction with triphenylphosphine. The symmetrical 1,3,4-thia-diazoline represents the normal direction of cycloaddition, but the orientation of addition of diazomethane to adamantanethione is governed by the nature of the solvent, and the unsymmetrical adduct predominates in solvents of higher polarity. A -l,3,4-Thiadiazoline-2,5-dione (148) is generated by oxidation of... 

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