Ethyl Acetate → 8-Chloro-5,7-dimethyl-3,4-dihydrospiro[chromene-2,1'-cyclobutan]-6-ol

HRID 2102983Notes

Reaction equation

HRID 2102983 reaction equation
[CH3:1][C:2]1[C:14]([OH:15])=[C:13]([CH3:16])[CH:12]=[C:11]2[C:3]=1[CH2:4][CH2:5][C:6]1([O:10]2)[CH2:9][CH2:8][CH2:7]1.S(Cl)([Cl:20])(=O)=O.C(OCC)(=O)C>C(OCC)C>[Cl:20][C:12]1[C:13]([CH3:16])=[C:14]([OH:15])[C:2]([CH3:1])=[C:3]2[C:11]=1[O:10][C:6]1([CH2:7][CH2:8][CH2:9]1)[CH2:5][CH2:4]2

Participants

5

Reactant 3

HCID 8857Ethyl AcetateHCID 24648Sulfuryl chlorideHCID 115502985,7-Dimethyl-3,4-dihydrospiro[chromene-2,1'-cyclobutan]-6-ol

Product 1

HCID 578035038-Chloro-5,7-dimethyl-3,4-dihydrospiro[chromene-2,1'-cyclobutan]-6-ol

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a solution of 5,7-dimethyl-3,4-dihydrospiro[chromene-2,1′-cyclobutan]-6-ol (350 mg) in ethyl ether (6 mL) was added sulfonyl chloride (0.154 mL, 260 mg) dropwise at room temperature under nitrogen. After 2 hours, ethyl acetate was added, washed with an aqueous sodium bicarbonate solution, water and brine, and dried. Evaporation and chromatography (silica gel hexane-ethyl acetate 0% to 4%, hexane-dichloromethane 5% to 20%) yielded the desired compound. Crystallization with hexane gave colorless crystals of 8-chloro-5,7-dimethyl-3,4-dihydrospiro[chromene-2,1′-cyclobutan]-6-ol (60 mg). 1H-NMR (300 MHz, CDCl3) δ=4.29 (s, 1H), 2.67 (t, J=6.6 Hz, 2H), 2.35-1.80 (m, 13H), 1.75-1.60 (m, 1H) ppm. 13C-NMR (75 MHz, CDCl3) δ=145.2, 143.6, 120.9, 120.1, 119.9, 119.7, 77.3, 33.8, 29.2, 20.8, 13.2, 12.5, 11.5 ppm. MS: (m/z)=253 (100, M+H+), 275 (23, M+Na+).

Workup

  1. washwashed with an aqueous sodium bicarbonate solution, water and brine
  2. customdried
  3. customEvaporation and chromatography (silica gel hexane-ethyl acetate 0% to 4%, hexane-dichloromethane 5% to 20%)

Sources & evidence

ORD record
ord-faecfae9add14e69ae411ba34865ad12
Source dataset
uspto-grants-2009_08
Patent number
US07576094B2

Reaction notes

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