Sodium Carbonate → (rac.)-(1R*,5S*)-3-(4-Hydroxy-phenyl)-8-aza-bicyclo[3.2.1]oct-2-ene-2,8-dicarboxylic Acid 8-tert-butyl Ester 2-methyl Ester

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Reaction Steps

To a sol. of compound A1 (10.0 g, 24.1 mmol) and 4-hydroxybenzeneboronic acid (3.42 g, 24.1 mmol) in DME (171 mL) was added aq. 2 M Na2CO3 (86 mL). The mixture was stirred at rt for a few minutes, and Pd(PPh3)4 (1.39 g, 1.20 mmol) was added. The mixture was heated rapidly to 80° C., and stirred at this temperature for 60 min. The mixture was partitioned between EtOAc and water, and the aq. layer was extracted with EtOAc. The combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the crude by FC (heptane/EtOAc 6:4) yielded the title compound (7.70 g, 89%). LC-MS: tR=0.95 min, ES+: 360.18.

Provenance & Evidence