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

HRID 1723484

反応式

HRID 1723484 の反応式
[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

参加物

7

反応物 4

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

生成物 1

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

試薬・触媒・溶媒 2

HCID 180Acetone溶媒HCID 8857Ethyl Acetate溶媒

実験手順

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).

後処理

  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

出典と根拠

ORDレコード
ord-5f8fb694f48c44aa8d675497a03bd43b
出典データセット
uspto-grants-1989_08
特許番号
US04861892

関連ノート

読み込み中…