2,6-Lutidine → (1R,9S,15R,16E,18R,19R,21R,24E,26E,28E,30S,32S,35R)-12-[(2R)-1-[(3R,4R)-4-(2-ethoxyethoxy)-3-methoxycyclohexyl]propan-2-yl]-1,18-dihydroxy-19,30-dimethoxy-15,17,21,23,29,35-hexamethyl-11,36-dioxa-4-azatricyclo[30.3.1.04,9]hexatriaconta-16,24,26,28-tetraene-2,3,10,14,20-pentone

Participants

Reaction Steps

To a stirred solution of 1 g rapamycin, and 7.66 g 2,6-lutidine in 14.65 mL toluene held at 60° C. was added 5.81 g 2-ethoxyethanol triflate. Stirring was continued for 90 minutes after which 50 mL ethyl acetate was added to the reaction and the solution was washed with 50 mL 1M HCl. The organic material was washed with D.I. water until pH of wash solution was neutral and the organic solution was dried over anhydrous sodium sulfate, filtered, and concentrated. The residue was purified by flash chromatography on silica gel, 200–400 mesh (40:60 hexane-ethyl acetate (v/v) to give 210 mg 42-O-(2-ethoxyethyl) rapamycin. TLC Rf=0.41 using 40:60 hexane-ethyl acetate (v/v). MS (ESI) m/z 1008.5 C55H87NNaO14. A mass spectrum of the title compound is shown in FIG. 1.

Provenance & Evidence