2-Acetylfuran → Lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate

HRID 2222601Notes

Reaction equation

[Li+:1].C[Si]([N-][Si](C)(C)C)(C)C.[C:11]([C:14]1[O:15][CH:16]=[CH:17][CH:18]=1)(=[O:13])[CH3:12].[C:19](OC(C)(C)C)(=[O:27])[C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21]>CCOCC>[C:23]([O:22][C:20](=[O:21])[C:19]([O-:27])=[CH:12][C:11]([C:14]1[O:15][CH:16]=[CH:17][CH:18]=1)=[O:13])([CH3:26])([CH3:25])[CH3:24].[Li+:1]

Participants

Conditions

Temperature: -78 °C

Procedure

Part A. A 1-L flame-dried flask was charged with 130 mL of LiHMDS (130 mmol; 1.0 M in THF) and 410 mL of ethyl ether. The resulting solution was cooled to −78° C. and 2-acetylfuran (14 g, 12 m mmol) was added in one portion. After 5 min, di-tert-butyl oxalate was added dropwise over 1 h as a solution in 100 mL of ether. The resulting mixture was warmed to 23° C. over a period of 3 h and was maintained at rt for 20 h. The mixture was then filtered, and the resulting beige precipitate was washed with 100 mL of ether. The filter cake was dried in a vacuum oven for 1 h to afford lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate (25 g, 83%) as a cream colored solid. 1H NMR (DMSO-d6) δ 7.75 (t, 1H), 6.96 (m, 1H), 6.56 (m, 1H), 3.34 (s, 2H), 1.46 (s, 9H).

Workup

dry with materialA 1-L flame-dried flask
temperatureThe resulting mixture was warmed to 23° C. over a period of 3 h
temperaturewas maintained at rt for 20 h
filtrationThe mixture was then filtered
washthe resulting beige precipitate was washed with 100 mL of ether
customThe filter cake was dried in a vacuum oven for 1 h

Sources & evidence

ORD record: ord-05e42bb3472846e19fecb93db37a1e02
Source dataset: uspto-grants-2008_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07371761B2

Reaction notes

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