Pentane → N-(6'-bromo-1'-(1-ethoxyvinyl)-4-methoxy-1',3'-dihydrospiro[cyclohexane-1,2'-indene]-1'-yl)-2-(trimethylsilyl)ethanesulfonamide

Participants

Reaction Steps

To a solution of ethyl vinyl ether (7 mL, 73 mmol) in THF (10 mL) was added dropwise a solution of 1.7 M t-BuLi in pentane (26 mL, 44 mmol) at −78° C. under nitrogen. After 10 min, the reaction mixture was cooled in an ice bath and stirred for 45 min. To a solution of N-(5′-bromo-4-methoxyspiro[cyclohexane-1,2′-indene]-3′(1′H)-ylidene)-2-(trimethylsilyl)ethanesulfonamide (2) (1.3508 g, 2.86 mmol) in THF (20 mL) was added a solution of -ethoxyvinyllithium, obtained as described above, at −78° C. under nitrogen via a cannula. After 2 h, LC-MS indicated the disappearance of starting material. The reaction mixture was quenched with saturated NaHCO3 (5 mL) and saturated brine (20 mL) and then vigorously stirred at room temperature for 1 h. The mixture was extracted three times with EtOAc. The combined organic layers were dried over Na2SO4, filtered and evaporated. The crude product 9 (1.7654 g) was directly used in the next step without further purification. LC-MS tR=2.43 min in 3 min chromatography, m/z 544, 546 (MH+), 480, 482.

Provenance & Evidence