Ammonium Chloride → 5-(1-hydroxyethyl)spiro[benzo[b]furan-2(3H), 1'-cyclopropane]-3-one

HRID 1065649Notes

Reaction equation

[C:1]([C:4]1[CH:15]=[CH:14][C:7]2[O:8][C:9]3([C:12](=[O:13])[C:6]=2[CH:5]=1)[CH2:11][CH2:10]3)(=[O:3])[CH3:2].[BH4-].[Na+].[Cl-].[NH4+]>O1CCCC1.C(O)(C)C>[OH:3][CH:1]([C:4]1[CH:15]=[CH:14][C:7]2[O:8][C:9]3([C:12](=[O:13])[C:6]=2[CH:5]=1)[CH2:11][CH2:10]3)[CH3:2]

Participants

Conditions

Temperature: -50 °C

Procedure

To a well stirred solution of 5-acetylspiro[benzo-[b]furan-2(3H), 1'-cyclopropane]-3-one (1 g) in tetrahydrofuran (25 ml) and isopropanol (3 ml) was added portionwise NaBH4 (0.9 g) cooling at -50° C. The reaction mixture was then stirred at room temperature for 30 minutes, followed by dilution with ice-water, which was neutralized with aqueous ammonium chloride. The aqueous solution was extracted with ethyl acetate. The extract was washed with water and dried. The residue obtained by removal of the solvent was chromatographed on silica gel, eluting with CHCl3. The product was distilled under reduced pressure to give 5-(1-hydroxyethyl)spiro[benzo[b]furan-2(3H), 1'-cyclopropane]-3-one as colorless oil. b.p. 0.05 mmHg: 110° C. (bath temperature). IRνmaxfilm cm-1 : 3350(OH), 1710 (CO). NMR (CDCl3)δ: 1.45 (3H, d, J=6 Hz, CH3), 1.62 (4H, q, J=3 Hz, CH2), 3.33 (1H, b, OH), 4.83 (1H, q, J=6 Hz, CH), 6.97 (1H, d, J=9 Hz, aromat.H), 7.55 (2H, m, aromat.H).

Workup

extractionThe aqueous solution was extracted with ethyl acetate
washThe extract was washed with water
customdried
customThe residue obtained by removal of the solvent
customwas chromatographed on silica gel
washeluting with CHCl3
distillationThe product was distilled under reduced pressure

Sources & evidence

ORD record: ord-acc763fb269f4dd2a2668e412b0b3c68
Source dataset: uspto-grants-1982_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04330554

Reaction notes

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