1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → (8S,11R,15R)-11-(((9H-fluoren-9-yl)methoxy)carbonylamino)-8-ethyl-2,2-dimethyl-4,10-dioxo-3,6-dioxa-13-thia-9-azahexadecane-15,16-diyl didodecanoate

Participants

Reaction Steps

To a solution of (5R,9R)-9-(dodecanoyloxy)-1-(9H-fluoren-9-yl)-3,12-dioxo-2,11-dioxa-7-thia-4-azatricosane-5-carboxylic acid (6, 1 eq) and (S)-tert-butyl 2-(2-aminobutoxy)acetate (1.5 eq, from the previous step) in 2:1 THF/DMF (0.13 M) was added EDCI (1.3 eq), HOBT (1.3 eq), and DIEA (5 eq). The reaction was stirred at room temperature overnight. The reaction mixture was diluted with ethyl acetate. The organic layer was washed with 2:1 saturated aqueous NaHCO3/water, brine, dried over anhydrous Na2SO4, and concentrated en vaccuo. The crude mixture was purified by flash chromatography on a COMBIFLASH® system (ISCO) using a gradient of 0-40% ethyl acetate in hexanes to give the product.

Provenance & Evidence