Cholesterol → HCID 86607619, compound

HRID 1445319Notes

Reaction equation

HRID 1445319 reaction equation
[CH:1]1(Br)[O:9][C@H:8]([CH2:10][OH:11])[C@H:6]([OH:7])[C@H:4]([OH:5])[C@H:2]1[OH:3].[CH3:13][CH:14]([CH2:16][CH2:17][CH2:18][C@H:19]([C@@H:21]1[C@:39]2([CH3:40])[C@H:24]([C@H:25]3[C@H:36]([CH2:37][CH2:38]2)[C@:34]2([CH3:35])[C:28]([CH2:29][C@H:30]([CH2:32][CH2:33]2)[OH:31])=[CH:27][CH2:26]3)[CH2:23][CH2:22]1)[CH3:20])[CH3:15]>ClCCl.FC(F)(F)S([O-])(=O)=O.[Ag+]>[C@@H:1]1([CH2:15][CH:14]([CH2:16][CH2:17][CH2:18][C@H:19]([C@@H:21]2[C@:39]3([CH3:40])[C@H:24]([C@H:25]4[C@H:36]([CH2:37][CH2:38]3)[C@:34]3([CH3:35])[C:28]([CH2:29][C@H:30]([CH2:32][CH2:33]3)[OH:31])=[CH:27][CH2:26]4)[CH2:23][CH2:22]2)[CH3:20])[CH3:13])[O:9][C@H:8]([CH2:10][OH:11])[C@H:6]([OH:7])[C@H:4]([OH:5])[C@H:2]1[OH:3]

Participants

5

Reactant 2

HCID 5997CholesterolHCID 18664939HCID 18664939, compound

Product 1

HCID 86607619HCID 86607619, compound

Reagents, catalysts & solvents 2

HCID 76223Silver(I) trifluoromethanesulfonateCatalystHCID 6344DichloromethaneSolvent

Procedure

Compound 4 (see FIG. 12) was prepared from galactose 1 that was treated with pivaloyl chloride in pyridine. Instead of the expected penta-pivaloyl derivative, the partially pivaloylated compound 2 was obtained in good yield and high purity without the need of chromatographic purification. The free hydroxyl group in compound 2 was protected by an acetyl group (→3). This was followed by treatment with hydrogen bromide in acetic acid to provide the galactosyl bromide 4. Bromide 4 was coupled with cholesterol 5 under promotion by silver trifluoromethanesulfonate in dichloromethane to provide the desired β-galactosyl-cholesterol 6 in a stereoselective manner (see FIG. 13). The β-anomeric configuration was demonstrated by 1-H NMR spectroscopy. The O-protecting groups were subsequently removed by treatment with sodium methoxide in a mixture of anhydrous dichloromethane and methanol to provide the cholesteryl β-D-galactopyranoside 7 as an amorphous solid.

Workup

  1. customin good yield
  2. customhigh purity without the need of chromatographic purification
  3. customto provide the galactosyl bromide 4

Sources & evidence

ORD record
ord-bc06666b6d644ce0bec31279f27044f4
Source dataset
uspto-grants-2010_02
Patent number
US07666846B2

Reaction notes

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