Hydrochloric Acid → ethyl 8-chloro-4-hydroxy-2-oxo-2',3',5',6'-tetrahydro-4H-spiro[naphthalene-1,4'-pyran]-3-carboxylate

HRID 2078348Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4](/[C:8](/[OH:15])=[CH:9]/[C:10]([O:12][CH2:13][CH3:14])=[O:11])[C:3]=1[C:16]1([C:22](OCC)=[O:23])[CH2:21][CH2:20][O:19][CH2:18][CH2:17]1.CC[O-].[Na+].Cl>CCO.CCOC(C)=O>[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]2[C:3]=1[C:16]1([CH2:17][CH2:18][O:19][CH2:20][CH2:21]1)[C:22](=[O:23])[CH:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:8]2[OH:15]

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of (Z)-ethyl 4-(2-chloro-6-(3-ethoxy-1-hydroxy-3-oxoprop-1-enyl)phenyl)-tetrahydro-2H-pyran-4-carboxylate (0.38 g, 0.99 mmol) in 5 mL EtOH was treated with NaOEt (freshly made from 0.1 g Na and 5 mL EtOH), and stirred at 60° C. for 2 hours. The mixture was cooled to room temperature and diluted with 100 mL EtOAc, neutralized with 5N HCl to pH 5, washed with water (20 mL), saturated NaCl (20 mL), dried over anhydrous sodium sulfate and concentrated. The concentrate was purified by column chromatography (10-40% EtOAc/hexane) to give 0.27 g yellow solid. MS m/e: (M+H)+ 337.

Workup

temperatureThe mixture was cooled to room temperature
washwashed with water (20 mL), saturated NaCl (20 mL)
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated
customThe concentrate was purified by column chromatography (10-40% EtOAc/hexane)

Sources & evidence

ORD record: ord-e1a7cdaec35d4332b440c3b98c97c35a
Source dataset: uspto-grants-2011_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07928139B2

Reaction notes

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