Boron trifluoride etherate → HCID 14329718, compound

HRID 2231904Notes

Reaction equation

HRID 2231904 reaction equation
C([O:3][C:4](=[O:25])[CH2:5][CH2:6][C:7]1([CH3:24])[CH2:12][CH2:11][C:10]2[CH:13]=[CH:14][C:15]([O:20]C(=O)C)=[C:16]([CH2:17][CH2:18][CH3:19])[C:9]=2[O:8]1)C.B(F)(F)F.[CH3:30][CH2:31][O:32]CC>C(O)(=O)C.CCOCC>[C:31]([C:14]1[C:15]([OH:20])=[C:16]([CH2:17][CH2:18][CH3:19])[C:9]2[O:8][C:7]([CH3:24])([CH2:6][CH2:5][C:4]([OH:3])=[O:25])[CH2:12][CH2:11][C:10]=2[CH:13]=1)(=[O:32])[CH3:30]

Participants

5

Reactant 2

HCID 8000Boron trifluoride etherateHCID 53956501HCID 53956501, compound

Product 1

HCID 14329718HCID 14329718, compoundYield 72.1%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 3283Diethyl EtherSolvent

Conditions

Temperature
105 °C

Procedure

To a stirred solution of 276 mg of racemic-7-acetoxy-3,4-dihydro-2-methyl-8-n-propyl-2H-1-benzopyran-2-propanoic acid ethyl ester in 2 ml of glacial acetic acid was added 0.21 ml of boron trifluoride etherate, at room temperature. The mixture was stirred at 105° C. for 24 hours then cooled and diluted with ether. The ether solution was washed with water and brine and processed in the usual manner given 298 mg of a yellow-brown oil. This material was chromatographed on 30 g of silica gel. Elution with 4:1 toluene-ethyl acetate afforded 183 mg (72.1%) of racemic-6-acetyl-3,4-dihydro-7-hydroxy-2-methyl-8-n-propyl-2H-1-benzopyran-2-propanoic acid as an off-white solid, mp 154°-156° C.

Workup

  1. customat room temperature
  2. temperaturethen cooled
  3. washThe ether solution was washed with water and brine
  4. customThis material was chromatographed on 30 g of silica gel
  5. washElution with 4:1 toluene-ethyl acetate

Sources & evidence

ORD record
ord-bb11eac6b598413c8ca6e03480a96fbf
Source dataset
uspto-grants-1988_11
Patent number
US04785017

Reaction notes

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