Boron tribromide → (1R,10R,11S,16S)-4-methoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-trien-6-ol

HRID 422148Notes

Reaction equation

HRID 422148 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:18](=[C:19]([O:21]C)[CH:20]=1)[O:17][CH2:16][C@H:15]1[C@@:6]2([CH3:26])[CH2:7][CH2:8][C@@H:9]2[C@:14]1([CH3:23])[CH2:13][CH2:12][CH2:11][C:10]2([CH3:25])[CH3:24].B(Br)(Br)Br>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:18](=[C:19]([OH:21])[CH:20]=1)[O:17][CH2:16][C@H:15]1[C@@:6]2([CH3:26])[CH2:7][CH2:8][C@@H:9]2[C@:14]1([CH3:23])[CH2:13][CH2:12][CH2:11][C:10]2([CH3:25])[CH3:24]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 53240452(1R,10R,11S,16S)-4,6-dimethoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-triene

Product 1

HCID 53240453(1R,10R,11S,16S)-4-methoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-trien-6-ol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of (1R,10R,11S,16S)-4,6-dimethoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-triene (Compound No. 42) (0.186 g, 0.519 mmol) in anhydrous CH2Cl2 (10 mL) at 0° C. under nitrogen, BBr3 (1.0 M in CH2Cl2, 0.54 mL, 0.54 mmol) was added dropwise. The solution was stirred at room temperature for 6 h. The reaction was quenched at 0° C. with anhydrous MeOH (6 mL) and evaporated. The residue was co-evaporated with MeOH (4×20 mL) and dried in vacuo. Purification by column chromatography on silica gel (Hexanes/EtOAc, 10:1) gave a product, which was triturated with MeOH (4.5 mL) to afford (1R,10R,11S,16S)-4-methoxy-1,11,15,15-tetramethyl-8-oxatetracyclo[8.8.0.02,7.011,16]octadeca-2,4,6-trien-6-ol (Compound No. 44) (86 mg, 49%) as a white solid. 1H NMR (CDCl3): δ 6.38 (d, 1H), 6.24 (d, 1H), 5.49 (s, 1H), 4.40 (dd, 1H), 4.16 (dd, 1H), 3.71 (s, 3H), 2.25 (dd, 1H), 1.78-1.38 (m, 9H), 1.29 (s, 3H), 1.16 (m, 1H), 1.05 (m, 1H), 0.94 (s, 3H), 0.87 (s, 3H), 0.85 (s, 3H). MS m/z 345 (C22H32O3+H+).

Workup

  1. customThe reaction was quenched at 0° C. with anhydrous MeOH (6 mL)
  2. customevaporated
  3. customdried in vacuo
  4. customPurification by column chromatography on silica gel (Hexanes/EtOAc, 10:1)
  5. customgave a product, which
  6. customwas triturated with MeOH (4.5 mL)

Sources & evidence

ORD record
ord-15ff7d9262f74929a77971033fdb495c
Source dataset
uspto-grants-2012_01
Patent number
US08101605B2

Reaction notes

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