6-Bromo-2',4',5',6'-tetrahydrospiro[chroman-2,3'-pyran]-4-one → 6-Cyclohexyl-2',4',5',6'-tetrahydrospiro[chroman-2,3'-pyran]-4-one

HRID 2096554Notes

Reaction equation

Br[C:2]1[CH:3]=[C:4]2[C:14](=[CH:15][CH:16]=1)[O:13][C:7]1([CH2:12][CH2:11][CH2:10][O:9][CH2:8]1)[CH2:6][C:5]2=[O:17].[Br-].[CH:19]1([Zn+])[CH2:24][CH2:23][CH2:22][CH2:21][CH2:20]1>C1COCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Cu]I>[CH:19]1([C:2]2[CH:3]=[C:4]3[C:14](=[CH:15][CH:16]=2)[O:13][C:7]2([CH2:12][CH2:11][CH2:10][O:9][CH2:8]2)[CH2:6][C:5]3=[O:17])[CH2:24][CH2:23][CH2:22][CH2:21][CH2:20]1

Participants

Conditions

Temperature: 160 °C

Procedure

Pd(PPh3)2Cl2 (60 mg) in a 40 mL tube under Ar was treated sequentially with 6-bromo-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (600 mg, 2.01 mmol) in THF (20 mL*3), CuI (600 mg) and cyclohexylzinc(II) bromide (8.1 mL, 4.02 mmol). The mixture was heated under microwave at 160° C. for 10 min. The reaction mixture was concentrated in vacuo to give the residue, which was purified by column chromatography to give 6-cyclohexyl-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (200 mg, 30%). 1H-NMR (CDCl3): 1.31 (t, 4H), 1.48 (m, 1H), 1.62 (m, 5H), 1.76 (d, 4H), 1.89 (m, 1H), 2.06 (d, 1H), 2.49 (s, 1H), 2.61 (m, 2H), 3.49 (m, 2H), 3.79 (m, 2H), 6.88 (d, 1H), 7.29 (d, 2H), 7.61 (s, 1H).

Workup

concentrationThe reaction mixture was concentrated in vacuo
customto give the residue, which
customwas purified by column chromatography

Sources & evidence

ORD record: ord-5a6b52f22a634a808b3d0c5df46958ea
Source dataset: uspto-grants-2013_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08450308B2

Reaction notes

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