SolutionsPreparation and Reactivity
1. Preparation
How would you prepare 1-propanethiol from 1-bromopropane? And ethyl propyl sulfide?
With NaSH (or with thiourea followed by basic hydrolysis), by SN2. For the sulfide, with sodium ethanethiolate, CH3CH2SNa.
2. Oxidation
What is obtained when dimethyl sulfide is oxidized with one equivalent of oxidant and with an excess?
With one equivalent, dimethyl sulfoxide (DMSO); with an excess, dimethyl sulfone.
3. Disulfide bridges
Which reaction links two cysteine residues of a protein? How can it be undone?
The oxidation of the two SH groups to a disulfide bridge, –S–S–. A reducing agent (for example, an excess of a thiol) breaks it and regenerates the two SH groups.