C-14 labelling of NVP RAD001 - A new rapamycin derivative

Article abstract of DOI:10.1002/(SICI)1099-1344(199901)42:1<29::AID-JLCR164>3.0.CO;2-5

An optimized fermentation process is described for the carbon-14 labelling of rapamycin. It is characterized by good reproducibility, high radiochemical purity and excellent yields. L-[¹⁴C₂]Pipecolic acid and (1R,3R,4R)-3,4-dihydroxy[1,7-¹⁴C₂]cyclohexane carboxylic acid ([¹⁴C₂]DHCCA) synthesized in an effective stereoselective approach proved to be highly suitable precursors for this purpose. In a final step [¹⁴C₄]rapamycin was converted by selective 14C(40)-O-alkylation to [¹⁴C₄]NVP RAD001, a highly interesting immunosuppressant.