Triphenylphosphine → 6-[6-Methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-4-methyl-hex-4-enoic Acid Methyl Ester

HRID 272110Notes

Reaction equation

HRID 272110 reaction equation
[CH3:1][O:2][C:3](=[O:24])[CH2:4][CH2:5][C:6]([CH3:23])=[CH:7][CH2:8][C:9]1[C:10]([OH:22])=[C:11]2[C:15](=[C:16]([CH3:20])[C:17]=1[O:18][CH3:19])[CH2:14][O:13][C:12]2=[O:21].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.N(C(OCC)=O)=NC(OCC)=O.[CH3:56][Si:57]([CH:60](O)[CH3:61])([CH3:59])[CH3:58]>C1COCC1>[CH3:1][O:2][C:3](=[O:24])[CH2:4][CH2:5][C:6]([CH3:23])=[CH:7][CH2:8][C:9]1[C:10]([O:22][CH2:61][CH2:60][Si:57]([CH3:59])([CH3:58])[CH3:56])=[C:11]2[C:15](=[C:16]([CH3:20])[C:17]=1[O:18][CH3:19])[CH2:14][O:13][C:12]2=[O:21]

Participants

6

Reactant 4

HCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 30062926-(4-Hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-4-methyl-hex-4-enoic acid methyl esterHCID 124478981-(Trimethylsilyl)ethanol

Product 1

HCID 670105946-[6-Methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-4-methyl-hex-4-enoic Acid Methyl EsterYield 86.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 6-(4-hydroxy-6-methoxy-7-methyl-3-oxo-1,3-dihydro-isobenzofuran-5-yl)-4-methyl-hex-4-enoic acid methyl ester (222 mg, 0.66 mmol), PPh3 (260 mg, 0.996 mmol), and diethyl azodicarboxylate (173 mg, 0.996 mmol) in THF (3 mL) at 0° C. was added a solution of trimethylsilyl ethanol (142 μL, 0.996 mmol) in THF (3 mL). The resulting yellow solution was allowed to warm up to room temperature and stirred overnight. The reaction was worked up by concentrating the solution to dryness and addition of ether and hexanes. Triphenylphosphine oxide was removed by filtration and the filtrate was concentrated and purified by silica gel chromatography to provide 248 mg of the desired product as a clear oil. 1H NMR (300 MHz, CDCl3) δ 0.03 (s, 9H), 1.18-1.30 (m, 2H), 1.81 (s, 3H), 2.18 (s, 3H), 2.25-2.33 (m, 2H), 2.37-2.45 (m, 2H), 3.42 (d, 2H, J=7 Hz), 3.62 (s, 3H), 3.77 (s, 3H), 4.25-4.35 (m, 2H), 5.13 (s, 2H), 5.12-5.22 (m, 1H).

Workup

  1. concentrationby concentrating the solution
  2. additionto dryness and addition of ether and hexanes
  3. customTriphenylphosphine oxide was removed by filtration
  4. concentrationthe filtrate was concentrated
  5. custompurified by silica gel chromatography

Sources & evidence

ORD record
ord-6ecbc75442f84336a07c27a2a3e49c35
Source dataset
uspto-grants-2008_11
Patent number
US07452901B2

Reaction notes

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