p-Toluenesulfonic acid → HCID 57857057, compound

Participants

Reaction Steps

(Z)-Methyl 7-((1R,2R,5S)-2-((R,E)-3-(benzo[b]thiophen-2-yl)-3-(tert-butyldiphenylsilyloxy)prop-1-enyl)-5-hydroxy-3-oxocyclopentyl)hept-5-enoate (11a, limiting reagent) is dissolved in DCM (0.1 M) under a nitrogen atmosphere. Dihydropyran (1.1 molar equivalent) is added, followed by a catalytic amount of p-toluenesulfonic acid. The reaction is stirred at room temperature under a nitrogen atmosphere and the reaction progress is monitored by TLC. Upon completion, brine is added to the reaction mixture and the layers are separated. The organic phase is dried over sodium sulfate, filtered, and the solvent is evaporated. The crude product is purified by flash chromatography on regular silica gel eluted with hexanes-ethyl acetate to afford the title intermediate 15a.

Provenance & Evidence