Ethyl trifluoromethanesulphonate → HCID 86747926, compound

HRID 1109798Notes

Reaction equation

HRID 1109798 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[K+].[CH2:11]([N:18]([C:29]1[C:41]2[CH:40]([C:42]3[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=3)[C:39]3[C:34](=[CH:35][CH:36]=[CH:37][CH:38]=3)[C:33]=2[CH:32]=[CH:31][CH:30]=1)[C@H:19]([C:25]([O:27][CH3:28])=[O:26])[CH2:20][C:21]([O:23][CH3:24])=[O:22])[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.[CH2:48](OS(C(F)(F)F)(=O)=O)[CH3:49]>C1COCC1>[CH2:48]([CH:20]([C:21]([O:23][CH3:24])=[O:22])[C@@H:19]([C:25]([O:27][CH3:28])=[O:26])[N:18]([CH2:11][C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1)[C:29]1[C:41]2[CH:40]([C:42]3[CH:43]=[CH:44][CH:45]=[CH:46][CH:47]=3)[C:39]3[C:34](=[CH:35][CH:36]=[CH:37][CH:38]=3)[C:33]=2[CH:32]=[CH:31][CH:30]=1)[CH3:49]

Participants

5

Reactant 3

HCID 67924Ethyl trifluoromethanesulphonateHCID 3251421Potassium bis(trimethylsilyl)amideHCID 67794893HCID 67794893, compound

Product 1

HCID 86747926HCID 86747926, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-74 °C

Procedure

To a stirred solution of 8.65 ml (5.2 mmol) KHMDS (0.6M solution in toluene) in 50 ml dry THF was added 1.96 g (4.0 mmol) of dimethyl N-benzyl-N-(9-phenylfluorenyl)-aspartate of Example 3 dissolved in 8 ml THF drop by drop at -74° C. under N2. The pale yellow solution was stirred at -74° C. for 45 minutes then 568 μl (4.4 mmol) EtOTf were added neat at once at -76° C. After 10 minutes the reaction was quenched with 3 ml MeOH and partitioned between 40 ml 1M H3PO4 and 50 ml Et2O. The water layer was extracted with 40 ml Et2O and the combined organic layers were dried (MgSO4) and evaporated. The residue was purified by flash-chromatography (Kieselgel, Hexane/EtAc 8:1) to yield a mixture of dimethyl 3-ethyl N-benzyl-N-(9-phenylfluorenyl)-aspartate (20:1 mixture of diastereomers). The diastereomers were separated by MPLC (Kieselgel, Hexane/EtOAc 15:1) to yield the desired compound.

Workup

  1. customAfter 10 minutes the reaction was quenched with 3 ml MeOH
  2. custompartitioned between 40 ml 1M H3PO4 and 50 ml Et2O
  3. extractionThe water layer was extracted with 40 ml Et2O
  4. dry with materialthe combined organic layers were dried (MgSO4)
  5. customevaporated
  6. customThe residue was purified by flash-chromatography (Kieselgel, Hexane/EtAc 8:1)
  7. customto yield
  8. customThe diastereomers were separated by MPLC (Kieselgel, Hexane/EtOAc 15:1)

Sources & evidence

ORD record
ord-8ebe7b4aaabe461cb529ddc7f4ae4526
Source dataset
uspto-grants-1994_06
Patent number
US05322942

Reaction notes

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