Boron trifluoride etherate → Benzyl 6-methoxy-7-((3aR,4S,7R,7aR)-7-methoxy-6,6-dimethyl-2-oxotetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-4-yloxy)-8-methyl-2-oxo-2H-chromen-3-ylcarbamate

HRID 1511423Notes

Reaction equation

HRID 1511423 reaction equation
B(F)(F)F.CCOCC.[OH:10][C:11]1[C:20]([CH3:21])=[C:19]2[C:14]([CH:15]=[C:16]([NH:23][C:24](=[O:33])[O:25][CH2:26][C:27]3[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=3)[C:17](=[O:22])[O:18]2)=[CH:13][C:12]=1[O:34][CH3:35].ClC(Cl)(Cl)C(=N)O[C@H:40]1[C@@H:45]2[O:46][C:47](=[O:49])[O:48][C@@H:44]2[C@@H:43]([O:50][CH3:51])[C:42]([CH3:53])([CH3:52])[O:41]1.C(N(CC)CC)C>C(Cl)Cl>[CH3:35][O:34][C:12]1[CH:13]=[C:14]2[C:19](=[C:20]([CH3:21])[C:11]=1[O:10][C@H:40]1[C@@H:45]3[O:46][C:47](=[O:49])[O:48][C@@H:44]3[C@@H:43]([O:50][CH3:51])[C:42]([CH3:53])([CH3:52])[O:41]1)[O:18][C:17](=[O:22])[C:16]([NH:23][C:24](=[O:33])[O:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[CH:15]2

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 8471TriethylamineHCID 25138788Benzyl 7-hydroxy-6-methoxy-8-methyl-2-oxo-2H-chromen-3-ylcarbamateHCID 67094064(3aR,4S,7R,7aR)-7-methoxy-6,6-dimethyl-2-oxo-tetrahydro-3aH-[1.3]dioxolo[4,5-c]pyran-4-yl 2,2,2-trichloroacetimidate

Product 1

HCID 25140397Benzyl 6-methoxy-7-((3aR,4S,7R,7aR)-7-methoxy-6,6-dimethyl-2-oxotetrahydro-3aH-[1,3]dioxolo[4,5-c]pyran-4-yloxy)-8-methyl-2-oxo-2H-chromen-3-ylcarbamateYield 95.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Boron trifluoride etherate (5.30 μL, 0.042 mmol) was added to 23a (50.0 mg, 0.14 mmol) and (3aR,4S,7R,7aR)-7-methoxy-6,6-dimethyl-2-oxo-tetrahydro-3aH-[1.3]dioxolo[4,5-c]pyran-4-yl 2,2,2-trichloroacetimidate (171 mg, 0.47 mmol) in anhydrous CH2Cl2 (3.00 mL). After stirring at room temperature for 14 hours, triethylamine (150 μL) was added and the solvent was concentrated. The residue was purified via column chromatography (SiO2, 40:1 CH2Cl2:Acetone) to give 25a as a colorless foam (74.0 mg, 95%): 1H NMR (CD2Cl2, 400 MHz) 8.29 (s, 1H), 7.64 (s, 1H), 7.47-7.39 (m, 5H), 6.91 (s, 1H), 5.52 (d, J=3.4 Hz, 1H), 5.26 (s, 2H), 5.23 (dd, J=8.4, 3.5 Hz, 1H), 4.95 (t, J=8.2 Hz, 1H), 3.92 (s, 3H), 3.60 (s, 3H), 3.33 (d, J=8.0 Hz, 1H), 2.42 (s, 3H), 1.38 (s, 3H), 1.33 (s, 3H); 13C NMR (CDCl3, 125 MHz) δ 157.6, 152.7, 152.1, 148.1, 144.8, 141.8, 134.5, 127.8, 127.7, 127.5, 127.3, 122.3, 120.2, 119.8, 115.1, 109.6, 105.2, 98.3, 82.0, 77.1, 66.5, 65.5, 59.4, 57.4, 55.1, 26.0, 20.9, 8.9; IR (film) νmax 2957, 2928, 2854, 2359, 2341, 1817, 1709, 1522, 1464, 1389, 1371, 1205, 1174, 1111, 1072, 1034, 957, 800 cm−1; HRMS (ESI+) m/z: [M+H]+ calcd for C28H29NO11, 556.1819; found, 556.1822.

Workup

  1. concentrationthe solvent was concentrated
  2. customThe residue was purified via column chromatography (SiO2, 40:1 CH2Cl2:Acetone)

Sources & evidence

ORD record
ord-bfcff0b7ab854cc9a391afd03b37583d
Source dataset
uspto-grants-2012_07
Patent number
US08212012B2

Reaction notes

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