Pentane → Diethyl 5-tert-butyldimethylsilyloxy-2-methylphenylphosphonate

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-tert-butyldimethylsilyloxy-2-methylphenyliodide 1-2 (250 mg, 0.72 mmol) in 5 mL of THF, chilled to −78 was added 0.85 mL of a 1.7 M solution of t-butyllithium in pentane (1.44 mmol). The resulting pale yellow solution was stirred at −78° C. for 30 min. Then diethyl chlorophosphate (0.13 mL, 0.86 mmol) in 2 mL THF was added via a cannula needle. The resulting mixture was stirred at −78° C. for 30 min, then diluted with aqueous NH4Cl and EtOAc. The organic layer was separated, washed with brine, dried (MgSO4) and evaporated. The resulting residue was subjected to MPLC on a 12 g column of SiO2 eluting with 15% EtOAc in hexanes (10 min) to provide diethyl 5-tert-butyldimethylsilyloxy-2-methylphenylphosphonate 1-3 as an oil. 1H NMR (300 MHz, DMSO-d6): δ 0.18 (s, 6H), 0.95 (s, 9H), 1.22 (t, 6H, J=6 Hz), 2.40 (d, 3H, J=1.5 Hz), 3.9-4.0 (m, 4H), 6.99 (dd, 1H, J=8, 2 Hz), 7.19 (m, 1H), 7.24 (m, 1H).

Provenance & Evidence