Methanol → (2S,4S)-1-Benzyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate

HRID 1414071Notes

Reaction equation

HRID 1414071 reaction equation
[C:1]([N:11]1[CH2:18][C@@H:17]([OH:19])[CH2:16][C@H:12]1[C:13]([OH:15])=[O:14])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].[CH3:20]O.S(=O)(=O)(O)O>C(Cl)(Cl)Cl>[C:1]([N:11]1[CH2:18][C@@H:17]([OH:19])[CH2:16][C@H:12]1[C:13]([O:15][CH3:20])=[O:14])([O:3][CH2:4][C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1)=[O:2]

Participants

5

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 688414(2S,4S)-1-((Benzyloxy)carbonyl)-4-hydroxypyrrolidine-2-carboxylic acid

Product 1

HCID 688413(2S,4S)-1-Benzyl 2-methyl 4-hydroxypyrrolidine-1,2-dicarboxylate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

6.5 g (0.024 mole) of N-carbobenzyloxy-cis-4-hydroxy-L-proline [J.A.C.S., 79, 189 (1957)] is dissolved in 65 ml. of methanol, stirred, and treated with 0.65 ml. of concentrated sulfuric acid. After stirring at room temperature for one-half hour, the solution is allowed to stand overnight. The bulk of solvent is removed on a rotary evaporator and the oily residue (13 g.) is taken up in 70 ml. of ether and washed with 35 ml. of 10% sodium bicarbonate solution. The wash is back extracted with 35 ml. of ether. The combined organic layers are dried (MgSO4), and the ether is evaporated to give 6.5 g. (96%) of product as a pale yellow viscous oil. [α]D25 -24° (c, 1% in chloroform).

Workup

  1. additiontreated with 0.65 ml
  2. customThe bulk of solvent is removed on a rotary evaporator
  3. washof ether and washed with 35 ml
  4. extractionThe wash is back extracted with 35 ml
  5. dry with materialThe combined organic layers are dried (MgSO4)
  6. customthe ether is evaporated
  7. customto give 6.5 g

Sources & evidence

ORD record
ord-a62aaeda397f4eccb37cc322885da3ea
Source dataset
uspto-grants-1981_02
Patent number
US04252943

Reaction notes

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