Methanol → 5,8-Dihydro-5,8-epoxynaphtho[2,3-d]-1,3-dioxole

HRID 1837670Notes

Reaction equation

[O:1]1[CH:5]=[CH:4][CH:3]=[CH:2]1.[Li][CH2:7][CH2:8][CH2:9][CH3:10].[CH3:11][OH:12].[OH2:13].[C:14]1([CH3:20])C=CC=CC=1>>[O:1]1[CH:5]2[CH:14]=[CH:20][CH:2]1[C:3]1[C:4]2=[CH:10][C:9]2[O:12][CH2:11][O:13][C:8]=2[CH:7]=1

Participants

Reactant 5

HCID 178418339Butyllithium

Product 1

HCID 147704315,8-Dihydro-5,8-epoxynaphtho[2,3-d]-1,3-dioxoleYield 54%

Conditions

Temperature: -78 °C

Procedure

To 3,4-dibromobenzo-1,3-dioxolane (1.54 g, 5.50 mmol) and furan (4 g, 58.8 mmol) in PhMe (55 mL) at −78° C. was added BuLi (2.2 mL, 2.5M in hexanes, 5.5 mmol) dropwise. The reaction was stirred for two hours at −78° C. and the allowed to warm to rt. After 3 hours, MeOH (2 mL) was added and the reaction mixture was poured into water. The organic layer was separated and the aqueous layer was extracted three times with Et2O. The combined organic layers were washed with brine, dried over MgSO4, and concentrated. Recrystallization from hexanes gave 25 (560 mg, 54%) as white crystals). Rf=0.47 on silica gel (30% ethyl acetate:hexanes); mp 111-112° C. (Et2O); IR (KBr, cm−1) 2895, 1455, 1292, 1138, 1038, 1014, 848; 1H NMR (400 MHz, CDCl3) δ 7.02 (2H, dd, J=0.9, 0.9 Hz), 6.82 (2H, s), 5.92 (1H, d, J=1.5 Hz), 5.87 (1H, d, J=1.5 Hz), 5.62 (2H, s); 13C NMR (400 MHz, CDCl3) δ 144.3, 143.3, 103.9, 101.1, 82.4. HRMS calcd for C11H8O2 (M+): 188.0473. Found: 188.0463.

Workup

temperatureto warm to rt
waitAfter 3 hours
customThe organic layer was separated
extractionthe aqueous layer was extracted three times with Et2O
washThe combined organic layers were washed with brine
dry with materialdried over MgSO4
concentrationconcentrated
customRecrystallization from hexanes

Sources & evidence

ORD record: ord-3c2e25d2aaac4dbe99d81f21f27a2670
Source dataset: uspto-grants-2004_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06784210B2

Reaction notes

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