Cesium carbonate → ethyl (7R,8S)-8-((S)-3-benzyloxycarbonylamino-2-oxo-pyrrolidin-1-yl)-1,4-dioxa-spiro[4.5]decane-7-carboxylate

HRID 2242322Notes

Reaction equation

HRID 2242322 reaction equation
C([O-])([O-])=O.[Cs+].[Cs+].[SH3+].[I-].[CH2:9]([O:16][C:17]([NH:19][C@H:20]([C:26](=[O:43])[NH:27][C@H:28]1[CH2:37][CH2:36][C:31]2([O:35][CH2:34][CH2:33][O:32]2)[CH2:30][C@H:29]1[C:38]([O:40][CH2:41][CH3:42])=[O:39])[CH2:21][CH2:22][S+](C)C)=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>CS(C)=O>[CH2:9]([O:16][C:17]([NH:19][C@H:20]1[CH2:21][CH2:22][N:27]([C@H:28]2[CH2:37][CH2:36][C:31]3([O:35][CH2:34][CH2:33][O:32]3)[CH2:30][C@H:29]2[C:38]([O:40][CH2:41][CH3:42])=[O:39])[C:26]1=[O:43])=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

5

Reactant 3

HCID 10796Cesium carbonateHCID 3015009SulfoniumHCID 86618126HCID 86618126, compound

Product 1

HCID 57978126ethyl (7R,8S)-8-((S)-3-benzyloxycarbonylamino-2-oxo-pyrrolidin-1-yl)-1,4-dioxa-spiro[4.5]decane-7-carboxylate

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

Example 1, Alternative Step 9c: Cs2CO3 (61.5 g, 0.19M, 1.5 eq) was placed in an round bottom flask and anhydrous DMSO (2.4 L) was added. Sulfonium salt 3 (80.0 g, 0.13M, 1.0 eq) was then added portionwise. Once the addition was complete the reaction mass was left to stir in the dark for 20 h. The reaction mass was then split in half and each half worked up separately: the reaction mass was diluted with EtOAc (2.0 L) and washed with brine (2 L), the organic phase was washed with brine (500 mL). The combined aq. layers were then washed EtOAc (500 mL). The combined organic phases were then washed with brine (3×750 mL). The second half of the reaction mass was treated in an identical manner and the combined organics dried over MgSO4 and concentrated to give ethyl (7R,8S)-8-{(3S)-3-Benzyloxycarbonylamino-2-oxo-pyrrolidin-1-yl}-1,4-dioxa-spiro[4.5]decane-7-carboxylate 4 as a light colored oil (56.5 g, 0.13M, ˜100 area-% purity) pure by NMR analysis. 1H-NMR: (300 MHz, CDCl3) δ 7.38-7.30 (m, 5H), 5.37 (br d, J 4.0 Hz, 1H), 5.11 (s, 2H), 4.27-4.18 (m, 1H), 4.17-3.82 (m, 8H), 3.32 (td, J 10.0Hz, 60.0 Hz, 1H), 3.23 (q, J 5.0 Hz, 1H), 2.63-2.57 (m, 1H), 2.42-2.25 (m, 2H), 1.94-1.68 (m, 5H), 1.25 (t, J 7.0 Hz, 3H). HPLC: YMC-Pack Pro C18 5 μm 4.6×150 mm, 0.05% TFA (20% MeOH, 80% H2O), to 0.05% TFA (20% MeOH, 80% MeCN), 0-100% 10 min gradient. 8.99 min (Compound 5, produced on column, 4.2 AP), 9.48 (Compound 4, 74.3 AP). HRMS: m/z 447.2127 [Calc: C23H31N2O7 447.2131].

Workup

  1. additionOnce the addition
  2. waitwas left
  3. customThe reaction mass was then split in half
  4. additionthe reaction mass was diluted with EtOAc (2.0 L)
  5. washwashed with brine (2 L)
  6. washthe organic phase was washed with brine (500 mL)
  7. washThe combined organic phases were then washed with brine (3×750 mL)
  8. additionThe second half of the reaction mass was treated in an identical manner
  9. dry with materialthe combined organics dried over MgSO4
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-863fffb27738418cafa82f5d062f9436
Source dataset
uspto-grants-2010_03
Patent number
US07671062B2

Reaction notes

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