Methanol → HCID 18664735, compound

HRID 482308Notes

Reaction equation

HRID 482308 reaction equation
[CH2:1]([O:8][C:9](=[O:26])[C@H:10]([CH2:24][OH:25])[N:11]([O:15][C:16](=[O:23])[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)C(O)=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CN(C)[CH:29]=[O:30].[CH2:32]([O:39][C@H:40]1[C@H:45]([O:46][CH2:47][C:48]2[CH:53]=[CH:52][CH:51]=[CH:50][CH:49]=2)[C@H:44]([O:54][CH2:55][C:56]2[CH:61]=[CH:60][CH:59]=[CH:58][CH:57]=2)[C@H:43]([CH3:62])[O:42][CH:41]1Br)[C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1.C[OH:65]>[Br-].C([N+](CC)(CC)CC)C.ClCCl>[CH2:1]([O:8][C:9](=[O:26])[C@H:10]([CH2:24][O:25][C@@H:41]1[O:42][C@@H:43]([CH3:62])[C@@H:44]([O:54][CH2:55][C:56]2[CH:61]=[CH:60][CH:59]=[CH:58][CH:57]=2)[C@@H:45]([O:46][CH2:47][C:48]2[CH:53]=[CH:52][CH:51]=[CH:50][CH:49]=2)[C@@H:40]1[O:39][CH2:32][C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1)[NH:11][O:15][C:16](=[O:23])[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][C:22]=1[C:29]([OH:30])=[O:65])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 887MethanolHCID 6228DimethylformamideHCID 11113809HCID 11113809, compoundHCID 57036189HCID 57036189, compound

Product 1

HCID 18664735HCID 18664735, compoundYield 85%

Reagents, catalysts & solvents 2

HCID 6285Tetraethylammonium BromideCatalystHCID 6344DichloromethaneSolvent2×

Procedure

(FIG. 2-A). N-carboxybenzoyloxy-L-serine benzyl ester (dried under vacuum overnight with phosphorus pentoxide, 5.04 g, 15.3 mmol) and tetraethylammonium bromide (3.47 g, 16.83 mmol) were dissolved in dichloromethane (30 mL) and dimethylformamide (2 mL) containing crushed 4A molecular sieves (15 g). The solution was stirred under argon for thirty minutes. To this slurry was added freshly prepared 2,3,4-tri-O-benzyl-fucopyranosyl bromide (U. Spohr and R. U. Lemieux, Carbohydr. Res., 174 (1988) 211). (38.3 mmol) in dichloromethane (20 mL) and the reaction allowed to stir for 15 hours under argon. Methanol (10 mL) was added and stirring continued for thirty minutes after which the reaction was filtered, diluted with dichloromethane, and washed with water and brine. After drying and solvent removal, the residue was chromatographed (3:1 hexane:ethyl acetate) to give N-(carboxybenzoyloxy)-3-O-(2,3,4-tri-O-benzyl-a-L-fucopyranosyl)-L-serine benzyl ester (9.49 g, 85%) as an oil which solidified upon standing, [a]D -57.7 (c=0.91, chloroform), Rf =0.30 (3:1 hexane:ethyl acetate). 1H-NMR (CDCl3): ε 7.10-7.15 (m, 25 H, Ph), 6.09 (d, 1 H, JNH,CH =9.5 Hz, NH), 5.23 (d, 1 H, Jgem =11.5 Hz, PhCH2), 5.13 (s, 2 H, PhCH2), 5.05, 4.92, 4.76, 4.77 (d, 1 H, Jgem =11.5 Hz, PhCH2), 4.52-4.69 (m, 5 H, 3 PhCH2, serine CHNH, H-1), 4.16 (dd, 1 H, Jgem =10 Hz, Jvic =2.5 Hz, serine CH2), 3.94 (dd, 1 H, J1,2 =4 Hz, J2,3 =10 Hz, H-2), 3.60 (dd, 1H, J2,3 =10 Hz, J3,4 =2.5 Hz, H-3), 3.48 (d, 1 H, Jgem =10 Hz, Jvic =3.5 Hz, serine CH2), 3.29-3.40 (m, 2 H, H-4, H-5), 0.91 (d, 3H, J5,6 =6.5 Hz). 13C-NMR: ε170.10 (C=O ester), 156.30 (C=O), carbamate), 138.88, 138.53, 136.35, 135.51 (Ph quat.), 128.62, 128.57, 128.50, 128.38, 128.19, 128.14, 127.83, 127.64, 127.54 (Ph methine) 98.87 (C-1), 78.87 (C-4), 77.36 (C-3), 76.50 (C-2), 74.74, 73.31, 73.23 (PhCH2), 69.03 (serine CH2), 67.15, 67.07 (PhCH2), 66.68 (C-5), 54.51 (serine CHNH), 16.48 (C-6).

Workup

  1. stirringto stir for 15 hours under argon
  2. stirringstirring
  3. waitcontinued for thirty minutes
  4. filtrationafter which the reaction was filtered
  5. additiondiluted with dichloromethane
  6. washwashed with water and brine
  7. customAfter drying
  8. customsolvent removal
  9. customthe residue was chromatographed (3:1 hexane:ethyl acetate)

Sources & evidence

ORD record
ord-383e402b812e41e18e39c082b2cbc9c5
Source dataset
uspto-grants-1998_08
Patent number
US05795958

Reaction notes

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