Sulfuric Acid → (3aR,4S,-5R,6aS)-4-acetylhexahydro-5-methyl-2H-cyclopenta[b]furan-2-one

HRID 247503Notes

Reaction equation

HRID 247503 reaction equation
[Na].[N+]([CH:5]([C@@H:7]1[C@@H:14]2[C@@H:10]([O:11][C:12](=[O:15])[CH2:13]2)[CH2:9][C@H:8]1[CH3:16])[CH3:6])([O-])=O.[N+](=C)([O-])[O-:18].S(=O)(=O)(O)O>CO.O.C(O)(=O)C>[C:5]([C@@H:7]1[C@@H:14]2[C@@H:10]([O:11][C:12](=[O:15])[CH2:13]2)[CH2:9][C@H:8]1[CH3:16])(=[O:18])[CH3:6]

Participants

8

Reactant 4

HCID 1118Sulfuric AcidHCID 5360545SodiumHCID 13560253(3aR,4S,5R,6aS)-4-(1-nitroethyl)hexahydro-5-methyl-2H-cyclopenta[b]furan-2-oneHCID 178486260Methanenitronate

Product 1

HCID 13560255(3aR,4S,-5R,6aS)-4-acetylhexahydro-5-methyl-2H-cyclopenta[b]furan-2-one

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 887MethanolSolvent3×HCID 962WaterSolvent

Procedure

Sodium (1.3 g) was dissolved in methanol (30 mL) and the solution added at 0° to a methanol (40 mL) solution of the crude, optically active (3aR,4S,5R,6aS)-4-(1-nitroethyl)hexahydro-5-methyl-2H-cyclopenta[b]furan-2-one (10.0 g). This nitronate anion solution was added, 30 minutes later and at -30°, to a cold (-30°) solution of concentrated sulfuric acid (6 mL) in methanol (40 mL). The resulting mixture was processed as in Example III, including hydrolysis with acetic acid (8 mL) in water (30 mL) while stripping, to give 8.47 g (99%) of the crude, optically active (3aR,4S,-5R,6aS)-4-acetylhexahydro-5-methyl-2H-cyclopenta[b]furan-2-one as a yellow oil. This material was used directly in Example XIV.

Workup

  1. customat -30°

Sources & evidence

ORD record
ord-4f4c042282884848bc7fb22e37a9edcf
Source dataset
uspto-grants-1987_11
Patent number
US04707555

Reaction notes

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