17-Ethyl-1,14,20-trihydroxy-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 → 17-Ethyl-1,20-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-14,18-diene-2,3,10,16-tetraone

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 17-ethyl-1,14,20-trihydroxy-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 (in benzene) is added p-toluenesulfonic acid and the mixture warmed to 60° C. in an oil bath. The reaction mixture is cooled to room temperature, neutralized by the addition of a saturated aqueous NaHCO3 solution and extracted with ethyl acetate (3 times). The combined organics are washed with saturated NaCl solution, dried over Na2SO4 and purified by flash chromatography on silica gel (20% hexanes in ethyl acetate and 1% MeOH) to yield the title compound.

Provenance & Evidence