17-Ethyl-1,14-dihydroxy-12-[1-(4-hydroxy-3-methoxycyclohexyl)prop-1-en-2-yl]-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-tetrone → 17-Ethyl-1-hydroxy-12-[2'-(4"-triisopropylsilyloxy-3"-methoxycyclohexyl)-1'-methylvinyl]-14-triisopropylsilyloxy-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

Participants

Reaction Steps

To a cooled solution (0° C.) of 17-ethyl-1,14-dihydroxy-12-[2'-(4"-hydroxy-3"-methoxycyclohexyl)-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 (120 mg) in dry methylene chloride (15 ml) was added 2,6-lutidine (64.3 mg) followed by triisopropylsilyl trifluoromethanesulfonate (184 mg). Reaction temperature was raised to r.t. and stirred overnight under nitrogen atmosphere. The reaction was quenched with 10 ml of water and extracted with ethyl acetate. Organic layer was washed (water, sat'd NaHCO3, sat'd NaCl) and dried (anhydrous MgSO4). Removal of solvent followed by chromatography on silica gel (70% hexane/ethyl acetate) gave 150 mg of product. MASS: (FAB) 1110 (M+ +Li).

Provenance & Evidence