Chlorotrimethylsilane → tert-butyl 2-(1-hydroxy-4-methyl-6-(tetrahydro-2H-pyran-2-yloxy)-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate

Participants

Reaction Conditions

Reaction Steps

To a suspension of zinc powder (2.81 g, 43.35 mmol) in dry THF was added TMSCl (0.94 g, 8.67 mmol) at 40° C. The mixture was stirred at 55° C. for 15 min. The mixture was allowed to cooled to 30° C. and tert-butyl 2-bromoacetate (6.76 g, 34.68 mmol) was added slowly to the reaction mixture between 37-40° C. After completion of addition, the resulting mixture was stirred at room temperature for an additional 30 min. To a solution of 2-methyl-4-(tetrahydro-2H-pyran-2-yloxy)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzaldehyde (3 g, 8.67 mmol) in 20 mL dry THF at −78° C. was added dropwise the above prepared reaction mixture. The reaction mixture was stirred at room temperature for 1 h and quenched by ice-water at 0° C. The mixture was extracted with EtOAc (3×15 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was purified by silica gel column (EA:PE=1:10) to give 2.2 g of desired product as a light yellow oil.

Provenance & Evidence