Hydrochloric Acid → (2SR,9aRS)-9a-butyl-2,7-dihydroxy-4-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one

HRID 7867Notes

Reaction equation

[CH2:1]([C:5]12[CH2:17][CH:16]([OH:18])[C:15](=[O:19])[C:14]([CH3:20])=[C:13]1[C:12]1[C:7](=[CH:8][C:9]([O:21]COC)=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4].Cl>CO.CCOC(C)=O>[CH2:1]([C:5]12[CH2:17][CH:16]([OH:18])[C:15](=[O:19])[C:14]([CH3:20])=[C:13]1[C:12]1[C:7](=[CH:8][C:9]([OH:21])=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4]

Participants

Conditions

Temperature: 80 °C

Procedure

A solution of (2SR,9aRS)-9a-butyl-2-hydroxy-7-methoxymethoxy-4-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one (73 mg, 0.22 mmol) in methanol (5 mL) was placed under a nitrogen atmosphere, treated with 2N aqueous HCl (0.33 mL, 0.66 mmol), and stirred with heating in an oil bath at 80° C. for 30 minutes. After cooling to room temperature, the reaction mixture was diluted with EtOAc, washed with 5% aqueous NaHCO3 and brine, dried over MgSO4, filtered, and concentrated under vacuum to an oil. The crude product was purified by PLC on a 0.1×20×20 cm silica gel GF plate, developing twice with 4:1 hexanes-EtOAc. The band at Rf 0.12-0.20 was eluted with EtOAc and the eluant evaporated under vacuum to a gum (50 mg). This material crystallized from benzene to afford (2SR,9aRS)-9a-butyl-2,7-dihydroxy-4-methyl-1,2,9,9a-tetrahydro-3H-fluoren-3-one as a white solid.

Workup

temperatureAfter cooling to room temperature
washwashed with 5% aqueous NaHCO3 and brine
dry with materialdried over MgSO4
filtrationfiltered
concentrationconcentrated under vacuum to an oil
customThe crude product was purified by PLC on a 0.1×20×20 cm silica gel GF plate
washThe band at Rf 0.12-0.20 was eluted with EtOAc
customthe eluant evaporated under vacuum to a gum (50 mg)
customThis material crystallized from benzene

Sources & evidence

ORD record: ord-72dc067bf29f4615811dcb079c390574
Source dataset: uspto-grants-2006_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07087599B2

Reaction notes

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