Boron trifluoride etherate → 2-Bromoethyl 2,3,6-tri-O-acetyl-4-O-{2,3,6-tri-O-acetyl-4-O-[2,3,4-tri-O-acetyl-6-O-(2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl)-alpha-D-glucopyranosyl]-alpha-D-glucopyranosyl]-beta-D-glucopyranoside

HRID 653343Notes

Reaction equation

HRID 653343 reaction equation
[C:1]([O:4][C@@H:5]1[O:82][C@H:81]([CH2:83][O:84][C:85](=[O:87])[CH3:86])[C@@H:16]([O:17][C@@H:18]2[O:75][C@H:74]([CH2:76][O:77][C:78](=[O:80])[CH3:79])[C@@H:29]([O:30][C@H:31]3[O:48][C@H:47]([CH2:49][O:50][C@H:51]4[O:68][C@H:67]([CH2:69][O:70][C:71](=[O:73])[CH3:72])[C@@H:62]([O:63][C:64](=[O:66])[CH3:65])[C@H:57]([O:58][C:59](=[O:61])[CH3:60])[C@H:52]4[O:53][C:54](=[O:56])[CH3:55])[C@@H:42]([O:43][C:44](=[O:46])[CH3:45])[C@H:37]([O:38][C:39](=[O:41])[CH3:40])[C@H:32]3[O:33][C:34](=[O:36])[CH3:35])[C@H:24]([O:25][C:26](=[O:28])[CH3:27])[C@H:19]2[O:20][C:21](=[O:23])[CH3:22])[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:6]1[O:7][C:8](=[O:10])[CH3:9])(=O)[CH3:2].[Br:88]CCO.B(F)(F)F.CCOCC.C(OCC)(=O)C.C(CC(C)(C)C)(C)C>ClCCl>[C:8]([O:7][C@@H:6]1[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:16]([O:17][C@H:18]2[O:75][C@H:74]([CH2:76][O:77][C:78](=[O:80])[CH3:79])[C@@H:29]([O:30][C@H:31]3[O:48][C@H:47]([CH2:49][O:50][C@H:51]4[O:68][C@H:67]([CH2:69][O:70][C:71](=[O:73])[CH3:72])[C@@H:62]([O:63][C:64](=[O:66])[CH3:65])[C@H:57]([O:58][C:59](=[O:61])[CH3:60])[C@H:52]4[O:53][C:54](=[O:56])[CH3:55])[C@@H:42]([O:43][C:44](=[O:46])[CH3:45])[C@H:37]([O:38][C:39](=[O:41])[CH3:40])[C@H:32]3[O:33][C:34](=[O:36])[CH3:35])[C@H:24]([O:25][C:26](=[O:28])[CH3:27])[C@H:19]2[O:20][C:21](=[O:23])[CH3:22])[C@@H:81]([CH2:83][O:84][C:85](=[O:87])[CH3:86])[O:82][C@H:5]1[O:4][CH2:1][CH2:2][Br:88])(=[O:10])[CH3:9]

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 108982-BromoethanolHCID 18516502EtOAc isooctaneHCID 886555281,2,3,6-tetra-O-acetyl-4-O-{2,3,6-tri-O-acetyl-4-O-[2,3,4-tri-O-acetyl-6-O-(2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl)-alpha-D-glucopyranosyl]-beta-D-glucopyranosyl}-beta-D-glucopyranose

Product 1

HCID 867416462-Bromoethyl 2,3,6-tri-O-acetyl-4-O-{2,3,6-tri-O-acetyl-4-O-[2,3,4-tri-O-acetyl-6-O-(2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl)-alpha-D-glucopyranosyl]-alpha-D-glucopyranosyl]-beta-D-glucopyranoside

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Compound 92 (12.54 g, 9.85 mmol) and 2-bromoethanol (2.5 g, 1.4 ml, 20 mmol) were dissolved in dichloromethane (50 ml). Borontrifluoride etherate (7.1 g, 6.3 ml, 50 mmol) was added dropwise at room temperature and the mixture was stirred until the reaction was finished (48 h, TLC: SiO2, ethyl acetate:isooctane 3:1). The mixture was washed (water, saturated sodium hydrogen carbonate), dried (Na2SO4) and evaporated. The residue (12.3 g) was chromatographed (SiO2, ethyl acetate:isooctane 3:2) to give 93 (4.95 g, 63% based on transformed 92 and unreacted 92 (5.05 g). Compound 93 had [α]D25 +109° (c 1.3, chloroform). 1H-NMR (CDCl3, Me4Si) δ 5.35, 5.28, 5.18 (3d, each 1H, J=3.8, 2.8 and 3.6 Hz, H1', H1", H1"'), 4.60 (d, 1H, J=7.9 Hz, H1), 3.42-3.49 (m, 2H, CH2 -Br). 13C-NMR (CDCl3, TMS) δ 170.6-169.3 (CO), 100.4 (Cl), 95.9, 95.7, 95.3 (Cl', Cl", Cl"'), 77.3. 75.0, 73.7, 72.7, 72.2, 71.9, 71.8, 70.7, 70.4, 70.1, 69.9, 69.8, 69.7, 69.4, 69.3, 68.9, 68.5, 68.4, 67.4, 63.0, 61.8, 29.9, 21.1-20.6.

Workup

  1. washThe mixture was washed (water, saturated sodium hydrogen carbonate)
  2. dry with materialdried (Na2SO4)
  3. customevaporated
  4. customThe residue (12.3 g) was chromatographed (SiO2, ethyl acetate:isooctane 3:2)

Sources & evidence

ORD record
ord-08c76fe2d94b4898a20eea2049bcf985
Source dataset
uspto-grants-1987_06
Patent number
US04675392

Reaction notes

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