Water → Chroman

HRID 568727Notes

Reaction equation

HRID 568727 reaction equation
CO[C:3]1[C:4](C)=[C:5](C)[C:6]2[O:11][C:10](CCN3CCNCC3)(C)[CH2:9][CH2:8][C:7]=2[C:21]=1C.O1CCCC1.C([Li])CCC.O>CCCCCC>[O:11]1[C:6]2[CH:5]=[CH:4][CH:3]=[CH:21][C:7]=2[CH2:8][CH2:9][CH2:10]1

Participants

6

Reactant 4

HCID 962WaterHCID 8028TetrahydrofuranHCID 139344873,4-dihydro-6-methoxy-2-[2-(piperazin-1-yl)ethyl]-2,5,7,8-tetramethyl-2H-benzopyranHCID 178418339Butyllithium

Product 1

HCID 136319Chroman

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

A solution composed of 2 g (6.02 mmol) of the 3,4-dihydro-6-methoxy-2-[2-(piperazin-1-yl)ethyl]-2,5,7,8-tetramethyl-2H-benzopyran obtained by the process of Example 12 and 50 ml of tetrahydrofuran was cooled to -40° C. in a nitrogen atmosphere and, to this solution, 4.7 ml of a 15% solution of n-butyllithium in hexane was added gradually. The resultant mixture was stirred at -40° C. for 30 minutes. Then, 6.65 millimoles of the halogenated terpene compound (X') was added gradually thereto, and the resultant mixture was stirred at -40° C. for 30 minutes. After raising the temperature gradually to room temperature, the reaction mixture was poured into water and extracted with diethyl ether. The ether layer was dried over anhydrous sodium sulfate, and low-boiling substances were distilled off under reduced pressure. The residue was purified by silica gel column chromatography to give the corresponding 3,4-dihydrobenzopyran derivative. The yield and physical characteristics for each derivative thus obtained are shown in Table 19.

Workup

  1. additionwas added gradually
  2. extractionextracted with diethyl ether
  3. dry with materialThe ether layer was dried over anhydrous sodium sulfate, and low-boiling substances
  4. distillationwere distilled off under reduced pressure
  5. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-603d48953fe74982bd16a49adfe58b50
Source dataset
uspto-grants-1988_03
Patent number
US04728650

Reaction notes

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