Nitrogen → 5-(2-Methyl-[1,3]dioxolan-2-yl)furan-2-carbaldehyde

참여 물질

반응 조건

반응 단계

In a flame dried round-bottomed flask equipped with a magnetic stir bar and under inert atmosphere (N2), to a solution of n-BuLi (14.6 mL of a 1.6M solution in hexane, 23.35 mmol) in THF (21 mL) at −78° C. was added dropwise a solution of 2-furan-2-yl-2-methyl-[1,3]dioxolane (3.00 g, 19.46 mmol) in THF (6.0 mL). The reaction mixture was then stirred for 1 h at −78° C. before DMF (4.52 mL, 58.38 mmol) was added dropwise. The reaction mixture was stirred for 1 h at −78° C. Sat. aq. NaH4Cl (50 mL) was added and the mixture was extracted with EA (2×50 mL). The combined org. extracts were dried over MgSO4, filtered, and the solvent was removed under reduced pressure to give 5.91 g of crude 5-(2-methyl-[1,3]dioxolan-2-yl)-furan-2-carbaldehyde as an orange oil. LC-MS-conditions 02: tR=0.75 min; [M+H]+=183.23. The crude material was dissolved, under inert atmosphere (N2) in MeOH (59.0 mL) and treated at 0° C., portionwise, over 20 min, with NaBH4 (1.53 g, 38.92 mmol in five equal portions). The reaction mixture was stirred at rt for 45 min. The reaction mixture was poured in water (80 mL) and the aq. layer was extracted with EA (2×60 mL). The combined org. extracts were dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (50:50 hept-EA) gave the title compound. TLC: rf (50:50 hept-EA)=0.27. LC-MS-conditions 02: tR=0.65 min; [M+H]+=185.28.

출처 및 근거