Trifluoromethanesulfonic acid → 17-Ethyl-1,14-dihydroxy-12-[2'-(4"-(tert-butyldimethylsiloxy)-3"-allyloxycyclohexyl)-1'-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9]octacos-18-ene-2,3,10,16-tetraone

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Reaction Steps

To a solution of 17-ethyl-1,14-dihydroxy-12-[2'-(4"-(tert-butyldimethylsiloxy)-3"-hydroxycyclohexyl)-1'-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9]octacos-18-ene-2,3,10,16-tetraone (290 mg in 3.9 ml 33% methylene chloride in cyclohexane) allyl trichloroacetimidate (131 mg neat) was added and the reagents allowed to mix for 5 minutes. Trifluoromethanesulfonic acid (6 μl neat) was added slowly via syringe and the mixture stirred at room temperature. After 5 days the reaction was diluted with ethyl acetate and quenched with saturated sodium bicarbonate. The layers were separated, and the organic layer was washed with brine then dried over magnesium sulfate. Purification of the concentrate by preparative TLC on silica gel (ethyl acetate:hexane (1:5)+1% methanol) gave the title compound (150 mg). 1H NMR consistent with the desired structure.

Provenance & Evidence