Boron tribromide → (2R,3R,4R,5S,6S)-2-(acetoxymethyl)-6-(4-chloro-3-(4- hydroxybenzyl)phenyl)tetrahydro-2H-pyran-3,4,5-triyl triacetate

HRID 72587Notes

Reaction equation

HRID 72587 reaction equation
[C:1]([O:4][C@H:5]1[C@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@H:8]([C:19]2[CH:24]=[CH:23][C:22]([Cl:25])=[C:21]([CH2:26][C:27]3[CH:32]=[CH:31][C:30]([O:33]CC)=[CH:29][CH:28]=3)[CH:20]=2)[O:7][C@@H:6]1[CH2:36][O:37][C:38](=[O:40])[CH3:39])(=[O:3])[CH3:2].B(Br)(Br)Br.C([O-])(O)=O.[Na+]>ClCCl>[C:1]([O:4][C@H:5]1[C@H:10]([O:11][C:12](=[O:14])[CH3:13])[C@@H:9]([O:15][C:16](=[O:18])[CH3:17])[C@H:8]([C:19]2[CH:24]=[CH:23][C:22]([Cl:25])=[C:21]([CH2:26][C:27]3[CH:28]=[CH:29][C:30]([OH:33])=[CH:31][CH:32]=3)[CH:20]=2)[O:7][C@@H:6]1[CH2:36][O:37][C:38](=[O:40])[CH3:39])(=[O:3])[CH3:2]

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 516892Sodium BicarbonateHCID 10415783(2R,3R,4R,5S,6S)-2-(Acetoxymethyl)-6-[4-chloro-3-(4-ethoxybenzyl)phenyl]tetrahydro-2H-pyran-3,4,5-triyl triacetate

Product 1

HCID 67115824(2R,3R,4R,5S,6S)-2-(acetoxymethyl)-6-(4-chloro-3-(4- hydroxybenzyl)phenyl)tetrahydro-2H-pyran-3,4,5-triyl triacetateYield 76.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
-30 °C

Procedure

To a stirred solution of acetic acid (2R,3R,4R,5S,6S)-3,4,5-triacetoxy-6-[4-chloro-3-(4-ethoxy-benzyl)-phenyl]-tetrahydro-pyran-2-ylmethyl ester (4.0 g, 6.93 mmol) prepared using the procedures described in J. Med. Chem. 2008, 51(5), 1145-49, in dichloromethane (40 mL) was added 1 molar solution of BBr3 (34.6 mL, 34.6 mmol) at −78° C. under nitrogen atmosphere. Reaction was stirred at −78° C. for 1.5 h and −30° C. for 1 h. Reaction mixture was poured over ice and neutralized with sat. NaHCO3 (20 mL), extracted with dichloromethane, concentrated and purified by silica gel column chromatography to furnish acetic acid (2R,3R,4R,5S,6S)-3,4,5-triacetoxy-6-[4-chloro-3-(4-hydroxy-benzyl)-phenyl]-tetrahydro-pyran-2-ylmethyl ester (2.9 g).

Workup

  1. customReaction
  2. customReaction mixture
  3. extractionextracted with dichloromethane
  4. concentrationconcentrated
  5. custompurified by silica gel column chromatography

Sources & evidence

ORD record
ord-06451e2209c24a318a437e9ea3e8f9e4
Source dataset
uspto-grants-2014_09
Patent number
US08828951B2

Reaction notes

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