Figure 45.
(a) Hydrogen sulfide (H2S/HS−) affords the sulfhydryl radical (HS•/S•−) by a variety of methods and adds reversibly to the parent compound to form the dimeric radical anion. (b) Dual catalytic/radical chain mechanism for the deoxygenation of cis-1,2-cyclopentanediol (22) to cyclopentanol 24) via cyclopentanone (23) in aqueous solutions (taken from Ref. [190]). (c) Dual radical chain mechanism for the deoxygenation of 2-hydroxycyclohexanone (29).