Fmoc-Ser-OtBu → Acetonitrile--water (1/1)

HRID 1838791Notes

Reaction equation

HRID 1838791 reaction equation
C([O:5][C:6](=O)[C@H:7](CO)[NH:8]C(OCC1C2C=CC=CC=2C2C1=CC=CC=2)=O)(C)(C)C.[C:29]([O:33][C:34](=[O:79])[C@H:35]([CH2:54][O:55][C@H:56]1[O:69][C@H:68]([CH2:70][O:71][C:72](=[O:74])[CH3:73])[C@H:63]([O:64][C:65](=[O:67])[CH3:66])[C@H:58]([O:59][C:60](=[O:62])[CH3:61])[C@H:57]1[NH:75][C:76](=[O:78])[CH3:77])[NH:36][C:37]([O:39][CH2:40][CH:41]1[C:53]2[CH:52]=[CH:51][CH:50]=[CH:49][C:48]=2[C:47]2[C:42]1=[CH:43][CH:44]=[CH:45][CH:46]=2)=[O:38])([CH3:32])([CH3:31])[CH3:30]>C(S([O-])(=O)=O)(F)(F)F.[Ag+].C(O)=O>[C:29]([O:33][C:34](=[O:79])[C@H:35]([CH2:54][O:55][C@H:56]1[O:69][C@H:68]([CH2:70][O:71][C:72](=[O:74])[CH3:73])[C@H:63]([O:64][C:65](=[O:67])[CH3:66])[C@H:58]([O:59][C:60](=[O:62])[CH3:61])[C@H:57]1[NH:75][C:76](=[O:78])[CH3:77])[NH:36][C:37]([O:39][CH2:40][CH:41]1[C:42]2[CH:43]=[CH:44][CH:45]=[CH:46][C:47]=2[C:48]2[C:53]1=[CH:52][CH:51]=[CH:50][CH:49]=2)=[O:38])([CH3:30])([CH3:31])[CH3:32].[OH2:5].[CH3:6][C:7]#[N:8]

Participants

6

Reactant 2

HCID 11003502Fmoc-Ser-OtBuHCID 14410205HCID 14410205, compound

Product 2

HCID 14410205HCID 14410205, compoundHCID 18373917Acetonitrile--water (1/1)Yield 79%

Reagents, catalysts & solvents 2

HCID 76223Silver(I) trifluoromethanesulfonateCatalystHCID 284Formic AcidSolvent

Procedure

Nα-(Fluoren-9-ylmethoxycarbonyl)-3-O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-α-D-galactopyranosyl)-L-serine tert-butyl ester 1 was prepared as previously described (Lemieux et al (1979), Ferrari et al. (1980)) by glycosylation of Nα-(Fluoren-9-ylmethoxycarbonyl)-L-serine tert-butyl ester (Vowimkel et al. (1967) Schultz et al. (1993)) with 3,4,6-tri-O-acetyl-2-azido-2-deoxy-p-D-galactopyranosyl chloride (obtained from tri-O-acetyl-D-galactal) (Shafizadseh et al. (1963)) using AgOTf as catalysts, followed by the reduction and acetylation of the 2-position (Paulsen et al. (1982)). The t-butyl ester of 1 (2 g, 2.8 mmol) was then deprotected in formic acid (76 ml) (Paulsen et al. (1989)). The solution was stirred for 10 h and evaporated. The residue was dissolved in MeOH (200 ml) and the acetyl groups of the sugar moiety were removed by adding, dropwise, a solution of 1% MeONa (pH 11) (Meinjohanns et al. (1995)). After 15 h, the medium was neutralized by a Dowex 50WX8 (H+) resin and the final product 2 purified on a reverse phase column (C18) using a gradient of water/MeCN 1.27 g (yield 79%).

Workup

  1. customevaporated
  2. dissolutionThe residue was dissolved in MeOH (200 ml)
  3. customthe acetyl groups of the sugar moiety were removed
  4. additionby adding
  5. waitAfter 15 h
  6. customthe final product 2 purified on a reverse phase column (C18)

Sources & evidence

ORD record
ord-80086cfe281d40d884c148bcf6b68ba1
Source dataset
uspto-grants-2004_01
Patent number
US06676946B2

Reaction notes

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