Selective Alkylation. DMSO is an important solvent in the synthesis of some macrolide antibiotics. In the clarythromycin process, it is the solvent used in the methylation step shown below.
In spite of the many hydroxyl groups available for alkylation, the hydroxyl moiety highlighted is selectively methylated in the process.
Related Resources
DMSO PharmaSolvent Product Sheet
Synthesis Corner: Learn More about alkylation reactions in DMSO