p-Toluenesulfonic acid → 2,3:5,6-Di-O-isopropylidene-L-gulonolactone

HRID 1723484

반응식

HRID 1723484 반응식
[CH2:1]([OH:12])[C@H:2]([OH:11])[C@H:3]1[O:8][C:6](=[O:7])[C@@H:5]([OH:9])[C@H:4]1[OH:10].CO[C:15](OC)([CH3:17])[CH3:16].[C:20]1(C)[CH:25]=CC(S(O)(=O)=O)=C[CH:21]=1.C(=O)(O)[O-].[Na+]>C(OCC)(=O)C.CC(C)=O>[CH3:16][C:15]1([CH3:17])[O:11][CH:2]([CH:3]2[O:8][C:6](=[O:7])[CH:5]3[O:9][C:20]([CH3:25])([CH3:21])[O:10][CH:4]23)[CH2:1][O:12]1

참가 물질

7

반응물 4

HCID 6101p-Toluenesulfonic acidHCID 64952,2-DimethoxypropaneHCID 439373L-Gulonic acid, gamma-lactoneHCID 516892Sodium Bicarbonate

생성물 1

HCID 5682882,3:5,6-Di-O-isopropylidene-L-gulonolactone수율 79%

시약·촉매·용매 2

HCID 180Acetone용매HCID 8857Ethyl Acetate용매

실험 절차

L-Gulonolactone (20.00 g, 112.3 mmol) was stirred with acetone (160 ml), 2,2-dimethoxypropane (40 ml) and a catalytic amount of p-toluenesulphonic acid under dry nitrogen for 36 h when t.l.c. (ethyl acetate) revealed no starting material (Rf 0.0) and one product (Rf 0.9). The reaction mixture was stirred with an excess of sodium bicarbonate and the solvent removed under reduced pressure. The residue was dissolved in dichloromethane (200 ml) and washed with water (3×200 ml). The organic extracts were dried (magnesium sulphate) and the solvent removed under reduced pressure to give a solid which was recrystallized from ethyl acetate to yield 2,3:5,6-di-O-isopropylidene-L-gulonolactone, (22.89 g, 79%), m.p. 151°-153° C. [α]D20 +68.4° (c, 1 in acetone) [lit. m.p. 153°-154° C. [α]D20 +91.5°]. δC (CDCl3), 173.3 (s, C-1), 114.7 (s), 110.5 (s), 80.9, 76.0, 75.7 and 75.2 (4×d, C-2, C-3, C-4 and C-5), 65.1 (d, C-6), 26.5 (q), 25.7 (q), 25.0 (q).

후처리

  1. customthe solvent removed under reduced pressure
  2. dissolutionThe residue was dissolved in dichloromethane (200 ml)
  3. washwashed with water (3×200 ml)
  4. dry with materialThe organic extracts were dried (magnesium sulphate)
  5. customthe solvent removed under reduced pressure
  6. customto give a solid which
  7. customwas recrystallized from ethyl acetate

출처 및 근거

ORD 기록
ord-5f8fb694f48c44aa8d675497a03bd43b
출처 데이터셋
uspto-grants-1989_08
특허 번호
US04861892

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