(4-Carboxybutyl)triphenylphosphonium bromide → (Z)-7,7-dimethyl-8-[(tetrahydro-2H-pyran-2-yl)oxy]-5-octenoic acid

HRID 1388876

반응식

HRID 1388876 반응식
[Br-].[C:2]([CH2:5][CH2:6][CH2:7][CH2:8][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([OH:4])=[O:3].C([Li])CCC.[CH3:33][C:34]([CH3:45])([CH2:37][O:38][CH:39]1[CH2:44][CH2:43][CH2:42][CH2:41][O:40]1)[CH:35]=O>CN(C)P(=O)(N(C)C)N(C)C.O1CCCC1.CCCCCC.[Cl-].[Na+].O>[CH3:33][C:34]([CH3:45])([CH2:37][O:38][CH:39]1[CH2:44][CH2:43][CH2:42][CH2:41][O:40]1)/[CH:35]=[CH:8]\[CH2:7][CH2:6][CH2:5][C:2]([OH:4])=[O:3]

참가 물질

8

반응물 3

HCID 161236(4-Carboxybutyl)triphenylphosphonium bromideHCID 132764582,2-Dimethyl-3-((tetrahydro-2H-pyran-2-yl)oxy)propanalHCID 178418339Butyllithium

생성물 1

HCID 13276460(Z)-7,7-dimethyl-8-[(tetrahydro-2H-pyran-2-yl)oxy]-5-octenoic acid수율 151.5%

시약·촉매·용매 4

HCID 8028Tetrahydrofuran용매2회HCID 8058Hexane용매HCID 12679Hexamethylphosphoramide용매HCID 57417360Sodium chloride; water용매

실험 절차

To a suspension of 4.43 g (10 mmols) of (4-carboxybutyl)triphenylphosphonium bromide in 20 ml of hexamethylphosphorictriamide and 28 ml of tetrahydrofuran was added dropwise at 0°-5° C., and under argon, 12 ml of 1.6 M butyllithium in hexane. The reaction mixture turned deep red in color. After stirring for 1 hr. at room temperature, 1.08 g (5.86 mmoles) of 2,2-dimethyl-3-[(tetrahydro-2H-pyran-2-yl)oxy]propanal (H. Marschall, et al., Chem. Ber. 107, 887 (1974)) in 3 ml of tetrahydrofuran was added. The resulting mixture was stirred for 17 hrs. at room temperature and then diluted with brine and extracted with hexane. The aqueous phase was acidified with a saturated solution of oxalic acid and extracted four times with ether. The ether extracts were combined, dried over anhydrous magnesium sulfate, filtered, and the solvent was removed in vacuo to yield 2.4 g of crude (Z)-7,7-dimethyl-8-[(tetrahydro-2H-pyran-2-yl)oxy]-5-octenoic acid which was subsequently converted into the methyl ester derivative by treatment with a freshly prepared ethereal solution of diazomethane. The crude ester (2.35 g), obtained after removal of the solvent, was chromatographed on a silica gel column. A mixture of hexane-ether (7:3) eluted 1.24 g (75.2%) of (Z)-7,7-dimethyl-8-[(tetrahydro-2H-pyran-2-yl)oxy]-5-octenoic acid methyl ester. This material was dissolved in 15 ml of methanol and treated with 0.5 ml of 2 N hydrochloric acid. The mixture was stirred for 3 hrs. at room temperature. Ca. 10 ml of methanol was evaporated in vacuo. The remaining solution was diluted with ether and poured into a saturated solution of sodium bicarbonate. The organic layer was washed with brine, dried (MgSO4), and concentrated under reduced pressure to yield 0.940 g of crude material. Chromatographic purification of the product on a silica gel column yielded 0.610 g (69.8%) of pure (Z)-8-Hydroxy-7,7-dimethyl-5-octenoic acid methyl ester (98.9% pure, by GC).

후처리

  1. additionwas added dropwise at 0°-5° C.
  2. stirringThe resulting mixture was stirred for 17 hrs
  3. extractionextracted with hexane
  4. extractionextracted four times with ether
  5. dry with materialdried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customthe solvent was removed in vacuo

출처 및 근거

ORD 기록
ord-15cc35abdaee4f9bb93b75f5eb585d10
출처 데이터셋
uspto-grants-1984_02
특허 번호
US04434101

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