Boron trifluoride etherate → Methyl 4,7,8,9-tetra-O-acetyl-N-acetyl-2-S-[6-(5-cholesten-3beta-yloxy)hexyl]-2-thio-D-neuraminate

HRID 903979Notes

Reaction equation

HRID 903979 reaction equation
B(F)(F)F.CCOCC.C(O[C:14]1([O:31][C@@H:30]([C@@H:32]([C@@H:37]([CH2:42][O:43][C:44](=[O:46])[CH3:45])[O:38][C:39](=[O:41])[CH3:40])[O:33][C:34](=[O:36])[CH3:35])[C@H:25]([NH:26][C:27](=[O:29])[CH3:28])[C@@H:20]([O:21][C:22](=[O:24])[CH3:23])[CH2:19]1)[C:15](=[O:18])[O:16][CH3:17])(=O)C.[CH3:47][CH:48]([CH2:50][CH2:51][CH2:52][C@H:53]([C@@H:55]1[C@:72]2([CH3:73])[C@H:58]([C@H:59]3[C@H:69]([CH2:70][CH2:71]2)[C@:67]2([CH3:68])[C:62]([CH2:63][C@@H:64]([O:74][CH2:75][CH2:76][CH2:77][CH2:78][CH2:79][CH2:80][SH:81])[CH2:65][CH2:66]2)=[CH:61][CH2:60]3)[CH2:57][CH2:56]1)[CH3:54])[CH3:49]>C(Cl)(Cl)Cl>[C:22]([O:21][C@@H:20]1[C@@H:25]([NH:26][C:27](=[O:29])[CH3:28])[C@H:30]([C@@H:32]([C@@H:37]([CH2:42][O:43][C:44](=[O:46])[CH3:45])[O:38][C:39](=[O:41])[CH3:40])[O:33][C:34](=[O:36])[CH3:35])[O:31][C:14]([S:81][CH2:80][CH2:79][CH2:78][CH2:77][CH2:76][CH2:75][O:74][C@H:64]2[CH2:65][CH2:66][C@@:67]3([CH3:68])[C:62](=[CH:61][CH2:60][C@@H:59]4[C@@H:69]3[CH2:70][CH2:71][C@@:72]3([CH3:73])[C@H:58]4[CH2:57][CH2:56][C@@H:55]3[C@H:53]([CH3:54])[CH2:52][CH2:51][CH2:50][CH:48]([CH3:47])[CH3:49])[CH2:63]2)([C:15](=[O:18])[O:16][CH3:17])[CH2:19]1)(=[O:24])[CH3:23]

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 10864413(1S,2R)-1-((2R,3R,4S)-3-acetamido-4,6-diacetoxy-6-(methoxycarbonyl)tetrahydro-2H-pyran-2-yl)propane-1,2,3-triyl triacetateHCID 867372786-(5-Cholesten-3beta-yloxy)-hexane-1-thiol

Product 1

HCID 86737279Methyl 4,7,8,9-tetra-O-acetyl-N-acetyl-2-S-[6-(5-cholesten-3beta-yloxy)hexyl]-2-thio-D-neuraminateYield 20.9%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Boron trifluoride etherate (700 μl, 5.5 mmol) is added to a solution of methyl 2,4,7,8,9-penta-O-acetyl-N-acetyl-D-neuraminate (1.01 g, 1.96 mmol) and 6-(5-cholesten-3β-yloxy)-hexane-1-thiol (0.98 g, 1.96 mmol) in dry chloroform (5 ml). The mixture is stirred under nitrogen for 5 hours at room temperature, and washed with aqueous sodium bicarbonate and water. The dried solution is concentrated to a residue which is put on a silica gel column and eluted with chloroform-ethyl ether-methanol (31:10:1). The β-anomer is isolated as a glass (400 mg), [α]D -38.5° (c 1.5, chloroform).

Workup

  1. washwashed with aqueous sodium bicarbonate and water
  2. concentrationThe dried solution is concentrated to a residue which
  3. washeluted with chloroform-ethyl ether-methanol (31:10:1)

Sources & evidence

ORD record
ord-947eaeccf0f6469780bd186885995525
Source dataset
uspto-grants-1980_10
Patent number
US04229441

Reaction notes

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