Potassium Carbonate → (-)-(12R)-tert-Butyldimethylsiyloxy-6,11R)-dimethyl-4-propyl-6,10,11,12-tetrahydrodipyrano[2,3-f

HRID 975537Notes

Reaction equation

HRID 975537 reaction equation
[OH:1][C:2]1[C:11]([C@H:12]([O:17][Si:18]([C:21]([CH3:24])([CH3:23])[CH3:22])([CH3:20])[CH3:19])[C@H:13]([CH3:16])[CH:14]=[CH2:15])=[C:10]2[C:5]([C:6]([CH2:26][CH2:27][CH3:28])=[CH:7][C:8](=[O:25])[O:9]2)=[C:4]2[O:29][C:30]([CH3:34])([CH3:33])[CH:31]=[CH:32][C:3]=12.C([O-])([O-])=O.[K+].[K+].[BH4-].[Na+]>C1COCC1.[Cl-].[Na+].O.[Hg](OC(C)=O)OC(C)=O>[Si:18]([O:17][C@H:12]1[C:11]2[C:10]3[O:9][C:8](=[O:25])[CH:7]=[C:6]([CH2:26][CH2:27][CH3:28])[C:5]=3[C:4]3[O:29][C:30]([CH3:33])([CH3:34])[CH:31]=[CH:32][C:3]=3[C:2]=2[O:1][C@H:14]([CH3:15])[C@H:13]1[CH3:16])([C:21]([CH3:24])([CH3:22])[CH3:23])([CH3:19])[CH3:20]

Participants

7

Reactant 3

HCID 11430Potassium CarbonateHCID 4311764Sodium borohydrideHCID 5468734(+)-5-Hydroxy-6-[(1'R)-tert-butyldimethylsilyloxy-(2'R)-methylbut-3'-enyl]-2,3-f]chromen-8-one

Product 1

HCID 384860(-)-(12R)-tert-Butyldimethylsiyloxy-6,11R)-dimethyl-4-propyl-6,10,11,12-tetrahydrodipyrano[2,3-fYield 82%

Reagents, catalysts & solvents 3

HCID 16683746DiacetyloxymercuryCatalystHCID 8028TetrahydrofuranSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

To a solution of 10 (812 mg, 1.68 mmol) in THF (80 mL) was added Hg(OAc)2 (534 mg, 1.68 mmol), and the mixture was stirred for 20 min at room temperature. K2CO3 (232 mg, 1.68 mmol) was then added, and the reaction mixture was stirred for 30 min, then cooled to -10° C. NaBH4 was added (420 g, 11.0 mmol), and the reaction was allowed to warm to room temperature and stir for an additional 15 min. Hexanes (20 mL) were then added, followed by brine (40 mL). The organic layer was separated, and the aqueous layer was extracted with EtOAc (2×25 mL). The combined organic layers were dried (MgSO4 ), concentrated under reduced pressure at room temperature, and then submitted to silica gel chromatography (solvent B) to give 11 (660 mg, 82%) as a glass: [α]D20 -41° (c 1.0, acetone); 1H NMR (CDCl3): δ -0.132, 0.256 (2s, 6H, --SiCH3), 0.792 [s, 9H, --C(CH3)3 ], 0.996 (t, 3H, J=7.3 Hz, CH2CH3), 1.05 (d, 3H, J=6.82 Hz, --CH3), 1.38 (d, 3H, J=6.35 Hz, --CH3 ), 1.45, 1.47 (2s, 6H, --C(CH3)2, 1.54-1.73 (m, 3H, H-11,-ch2 ch3), 2.87 (m, 2H, --CH2CH2CH3), 4.40 (m, 1H, H-10), 4.99 (d, H, J=2.1 Hz, H-12), 5.49 (d, 1H, J=10.0 Hz, H-7), 5.90 (s, 1H, H-3), 6.62 (d, 1H, J=10.0 Hz, H-8); 13C NMR (CDCl3): δ -0.91, -0.56, 13.89, 14.05, 18.46, 19.14, 23.10, 25.96, 27.75, 38.49, 39.02, 62.62, 72.91, 77.48, 102.77, 105.83, 106.75, 110.11, 116.63, 126.46, 151.18, 152.92, 153.05, 158.31, 160.54. Anal. Calcd for C28H40O5Si: C, 69.38; H, 8.32. Found C, 69.18; H, 8.25.

Workup

  1. stirringthe reaction mixture was stirred for 30 min
  2. temperaturecooled to -10° C
  3. temperatureto warm to room temperature
  4. stirringstir for an additional 15 min
  5. customThe organic layer was separated
  6. extractionthe aqueous layer was extracted with EtOAc (2×25 mL)
  7. dry with materialThe combined organic layers were dried (MgSO4 )
  8. concentrationconcentrated under reduced pressure at room temperature

Sources & evidence

ORD record
ord-4223a7cd75264e358613e20ed02f5613
Source dataset
uspto-grants-1997_03
Patent number
US05608085

Reaction notes

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