The Reaction of Various Steroid α-Bromo Ketones with Dimethyl Sulfoxide¹

Dimethyl Sulfoxide Oxidations

“…The following discussion will consider oxidations proceeding by pathway B, i.e., formation of the dimethylalkoxysulfonium salt III by direct nucleophilic displacement of a leaving group by DMSO. Applications of this technique to -halo esters (Br, Cl, I) or acids (34), phenacyl halides (48,59), benzyl halides (49, 68), primary sulfonates (49, 60, 68), primary iodides (37), and a limited number of secondary halides (35,67,92) and secondary tosylates (36,42,83) have been successful in a preparative sense. Oxidation never proceeds past the carbonyl, and other functional groups remain generally inert.…”

Oxidative methods in the synthesis of vicinal di- and polycarbonyl compounds

“…This reaction pathway is particularly typical of steroid derivatives. 140 Heating of 2-bromocyclohexanone and 2-bromocyclopentanone in DMSO at 100 8C gives 3-bromocyclohexane-1,2-dione and 3-bromocyclopentane-1,2-dione rather than the corresponding diketones. 141,142 Under these conditions, the bromo ketone 49 gives the diketone 50, which exists in the enol form, only in the presence of epichlorohydrin to bind the HBr that evolves.…”

Aspects of the Reduction of Double Bonds Using Cob (I)alamin as Catalys

“…From 3~-methoxy-4-cholestene the 3B-methoxy-4-cholesten-6-one was obtained in analogy to the procedure leading to 3/?-acetoxy-4-cholesten-6-one, see [6] Reducziun of 3~-methoxy-4-cholesten-6rr-ol (2). Following the procedure described earlier [ 11, 2.5 g (0.4 mol-equiv.)…”