p-Toluenesulfonic acid → HCID 57033897, compound

HRID 1284872Notes

Reaction equation

HRID 1284872 reaction equation
[CH3:1][O:2][C:3](=[O:33])[C:4]([F:32])([F:31])[CH2:5][C@H:6]([C@@H:8]1[C@:25]2([CH3:26])[C@H:11]([C@H:12]3[C@H:22]([CH2:23][CH2:24]2)[C@:20]2([CH3:21])[C:15]([CH2:16][C@@H:17]([O:27][C:28](=[O:30])[CH3:29])[CH2:18][CH2:19]2)=[CH:14][CH2:13]3)[CH2:10][CH2:9]1)[CH3:7].[N+](=C)=[N-].O1C=C[CH2:40][CH2:39][CH2:38]1.CC1C=CC(S(O)(=O)=O)=CC=1>CCOCC.O1CCOCC1>[CH3:1][O:2][C:3](=[O:33])[C:4]([F:31])([F:32])[CH2:5][C@H:6]([C@@H:8]1[C@:25]2([CH3:26])[C@H:11]([C@H:12]3[C@H:22]([CH2:23][CH2:24]2)[C@:20]2([CH3:21])[C:15]([CH2:16][C@@H:17]([O:27][CH:28]4[CH2:29][CH2:40][CH2:39][CH2:38][O:30]4)[CH2:18][CH2:19]2)=[CH:14][CH2:13]3)[CH2:10][CH2:9]1)[CH3:7]

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 9550DiazomethaneHCID 53911591HCID 53911591, compound

Product 1

HCID 57033897HCID 57033897, compoundYield 95%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 312751,4-DioxaneSolvent

Procedure

The difluoroester (5) (880 mg, 1.9 mmol) was treated with 2% KOH--MeOH (30 ml) at room temperature for 2 hr. The usual work-up (ether for extraction) gave a crude acid. This in ether (10 ml) was treated with etheral solution of diazomethane until the gas evolution was ceased. This solution was concentrated under reduced pressure to leave the residue. This is dioxane (10 ml) was treated with 2,3-dihydropyran (516 μl) and TsOH (10 mg) at room temperature for 3 hr. The usual work-up (ether for extraction) gave a crude product, which was applied to a column of silica gel (200 g). Elution with n-hexane-ether (15:1) provided the THP-ester (6) (907 mg, 95%), amorphous. 1H-NMR δ: 0.70 (3H, s, 18-H3), 1.03 (3H, s, 19-H3), 1.10 (3H, d, J=6 Hz, 21-H3), 3.53 (2H, m, THP), 3.86 (3H, s, --CO2CH3), 3.93 (1H, m, 3-H), 4.73 (1H, m, THP), 5.36 (1H, m, 6-H). 19F-NMR δ: +40.0. MS m/z: 424 (M+ -DHP), 406, 391.

Workup

  1. extractionThe usual work-up (ether for extraction)
  2. customgave a crude acid
  3. concentrationThis solution was concentrated under reduced pressure
  4. customto leave the residue
  5. extractionThe usual work-up (ether for extraction)
  6. customgave a crude product, which
  7. washElution with n-hexane-ether (15:1)

Sources & evidence

ORD record
ord-846541ee03e04e02a1c1ffe74f8d3867
Source dataset
uspto-grants-1986_01
Patent number
US04564474

Reaction notes

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