Synthesis of Gentamicin Minor Components: Gentamicin C1a and Gentamicin C2b

Gentamicin C1a and the minor isomer C2b have been reported to have favorable properties in terms of antibacterial activity and toxicity compared to the commercial mixture from which they have previously been isolated by preparative highperformance liquid chromatography. We report straightforward syntheses of both compounds from readily available sisomicin by selective oxidation of the side chain in ring I, hydrogenation of the double bond in ring I to give the 5 & PRIME;-epi series, inversion of configuration at position 5 & PRIME; under thermodynamic conditions, and installation of the 6 & PRIME;-amino group by reductive amination.

Automated summary

In this study, we report a straightforward synthesis of Gentamicin C1a and the minor isomer C2b from readily available sisomicin. These compounds exhibit favorable properties in terms of antibacterial activity and toxicity compared to the commercial mixture.