Sodium borohydride → HCID 57857007, compound

HRID 561738Notes

Reaction equation

HRID 561738 reaction equation
[C:1]([O:9][C@@H:10]1[CH2:18][C@@H:13]2[O:14][C:15](=[O:17])[CH2:16][C@@H:12]2[C@H:11]1/[CH:19]=[CH:20]/[C:21]([C:23]1[S:27][C:26]2[CH:28]=[CH:29][CH:30]=[CH:31][C:25]=2[CH:24]=1)=[O:22])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[BH4-].[Na+]>C1COCC1.CO>[C:1]([O:9][C@@H:10]1[CH2:18][C@@H:13]2[O:14][C:15](=[O:17])[CH2:16][C@@H:12]2[C@H:11]1/[CH:19]=[CH:20]/[C@H:21]([C:23]1[S:27][C:26]2[CH:28]=[CH:29][CH:30]=[CH:31][C:25]=2[CH:24]=1)[OH:22])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 4311764Sodium borohydrideHCID 57857028HCID 57857028, compound

Product 1

HCID 57857007HCID 57857007, compound

Reagents, catalysts & solvents 1

HCID 21899815MeOH tetrahydrofuranSolvent

Conditions

Temperature
-40 °C

Procedure

To a stirring solution consisting of (3aR,4R,5R,6aS)-4-((E)-3-(benzo[b]thiophen-2-yl)-3-oxoprop-1-enyl)-2-oxohexahydro-2H-cyclopenta[b]furan-5-yl benzoate (4a, limiting reagent) in 2:1 THF-methanol (0.1 M) cooled to −40° C. is added CeCl3 heptahydrate. The reaction mixture is subsequently cooled to −78° C. and sodium borohydride (2 molar equivalents) is added and the solution is stirred for 1.5 hours. The reaction is quenched by the addition of acetone at −60° C. followed by the addition of a saturated aqueous ammonium chloride solution as the reaction mixture slowly warms to room temperature. The reaction mixture is diluted with brine and acidified with a small amount of 5% aqueous KHSO4. The product is extracted with ethyl acetate twice and the combined organic layers are dried over sodium sulfate, filtered, and evaporated under reduced pressure. The crude product is purified by flash chromatography on regular silica gel eluted with hexanes-ethyl acetate to afford the title intermediate 5a.

Workup

  1. temperatureThe reaction mixture is subsequently cooled to −78° C.
  2. customThe reaction is quenched by the addition of acetone at −60° C.
  3. additionfollowed by the addition of a saturated aqueous ammonium chloride solution as the reaction mixture
  4. customslowly warms to room temperature
  5. additionThe reaction mixture is diluted with brine
  6. extractionThe product is extracted with ethyl acetate twice
  7. dry with materialthe combined organic layers are dried over sodium sulfate
  8. filtrationfiltered
  9. customevaporated under reduced pressure
  10. customThe crude product is purified by flash chromatography on regular silica gel
  11. washeluted with hexanes-ethyl acetate

Sources & evidence

ORD record
ord-a6e31e2405f7483dacb63e74717e3ba5
Source dataset
uspto-grants-2011_11
Patent number
US08063240B2

Reaction notes

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