Trimethylsilyl triflate → ethyl hexahydro-1'H-spiro[[1,3]dioxolane-2,2'-pentalene]-5'-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 5-oxooctahydropentalene-2-carboxylate (210 mg) in DCM (5 mL) cooled to −78° C. were added slowly trimethylsilyl trifluoromethanesulfonate (11.89 mg, 0.054 mmol) and 2,2,7,7-tetramethyl-3,6-dioxa-2,7-disilaoctane (287 mg, 1.391 mmol) under nitrogen. After stirring at −78° C. for 30 min, the reaction mixture was warmed to rt and stirred at rt for 16 h. The reaction was quenched with anhydrous pyridine at −78° C. followed by sat. NaHCO3, and then extracted with EtOAc. The combined organic layers were dried over anhydrous MgSO4 and concentrated in vacuo. The residue was purified by flash chromatography to afford ethyl hexahydro-1′H-spiro[[1,3]dioxolane-2,2′-pentalene]-5′-carboxylate (a mixture of endo/exo isomers) as a clear oil.

Provenance & Evidence