Methanol → methyl 2,3,5-tri-O-benzyl-L-xylofuranoside

HRID 1924026ノート

反応式

HRID 1924026 の反応式
[O:1]([CH3:11])[CH:2]1[O:8][C@@H:7]([CH2:9][OH:10])[C@@H:5]([OH:6])[C@@H:3]1O.[H-].[Na+].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.[CH3:22][OH:23]>O1CCCC1.[I-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:22]([O:23][C@H:3]1[C@H:5]([O:6][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[C@H:7]([CH2:9][O:10][CH2:14][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[O:8][CH:2]1[O:1][CH3:11])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

参加物

7

反応物 4

HCID 887MethanolHCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 12042993methyl L-xylofuranoside

生成物 1

HCID 11015596methyl 2,3,5-tri-O-benzyl-L-xylofuranoside収率 87%

試薬・触媒・溶媒 2

HCID 67553Tetrabutylammonium Iodide触媒HCID 8028Tetrahydrofuran溶媒

実験手順

To an ice-cold solution of 2 (10 g, 60.9 mmol) in dry tetrahydrofuran (350 mL) was added sodium hydride (60% dispersion in mineral oil, 14.8 g, 370 mmol) and the reaction mixture was stirred for 15 min under N2. To this reaction mixture was added solid tetrabutylammonium iodide (0.36 g, 0.96 mmol) followed by a dropwise addition of benzyl bromide (36.6 g, 214 mmol). The reaction mixture was stirred for 3 days at room temperature. After the addition of methanol (25 mL) the solution was evaporated under reduced pressure, and the crude product was purified by silica gel chromatography (cyclohexane/EtOAc, 9:1) to afford pure methyl 2,3,5-tri-O-benzyl-L-xylofuranoside (3, 23 g, 87% yield). MS 435 (M+H)+, 433 (M−H)+, 403 (M-OCH3)+; 1H NMR (CDCl3) δ 7.38-7.25 (m, 30H, aromatic H=s), 4.94 (d, 1H, H-1α, J1,2=4.3 Hz), 4.87 (d, 1H, H-1β, J1,2=0.9 Hz), 4.64-4.45 (m, 12H, PhCH2's), 4.37 (m, 1H, H-4α), 4.27 (dt, 1H, H-4β, J4,5a=3.7 Hz, J4,5b=6.5 Hz, J3,4=6.2 Hz), 4.17 (t, 1H, H-3α, J3,4=6.9 Hz, J2,3=5.6 Hz), 4.07 (dd, 1H, H-3β, J3,4=6.2 Hz, J2,3=2.5 Hz), 4.00 (dd, 1H, H-2α, J2,3=5.6 Hz), 3.95 (t, 1H, H-2β, J2,3=2.5 Hz), 3.70 (dd, 1H, H-5aα, J4,5a=4.5 Hz, J5a,5b=10.4 Hz), 3.66 (dd, 1H, H-5aβ, J4,5a=3.7 Hz, J5a,5b=10.7 Hz), 3.54 (dd, 1H, H-5bα, J4,5b=7.5 Hz), 3.49 (dd, 1H, H-5bβ, J4,5b=6.5 Hz).

後処理

  1. stirringThe reaction mixture was stirred for 3 days at room temperature
  2. customwas evaporated under reduced pressure
  3. customthe crude product was purified by silica gel chromatography (cyclohexane/EtOAc, 9:1)

出典と根拠

ORDレコード
ord-2c4a0c07f1054c0fb6f7f1d2f11424f7
出典データセット
uspto-grants-2012_05
特許番号
US08178510B2

反応ノート

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