Formaldehyde → 8-Oxo-2,2,5,7-tetramethyl-7-(hydroxymethyl)-3-oxa-1-azabicyclo[4.2.0]octane

HRID 224387Notes

Reaction equation

C([N-]C(C)C)(C)C.[Li+].[O:9]=[C:10]1[N:17]2[CH:12]([CH:13]([CH3:20])[CH2:14][O:15][C:16]2([CH3:19])[CH3:18])[CH:11]1[CH3:21].[CH2:22]=[O:23].[Cl-].[Na+]>O1CCCC1.O>[O:23]=[C:22]1[N:17]2[CH:12]([CH:13]([CH3:20])[CH2:14][O:15][C:16]2([CH3:18])[CH3:19])[C:11]1([CH3:21])[CH2:10][OH:9]

Participants

Conditions

Temperature: -78 °C

Procedure

To a solution of 1.1 equivalents of freshly prepared lithium diisopropylamide in anhydrous tetrahydrofuran under a nitrogen atmosphere at -78° is added a solution of 8-oxo-2,2,5,7-tetramethyl-3-oxa-1-azabicyclo[4.2.0]octane in anhydrous tetrahydrofuran which has been cooled to -78° C. After two minutes, the resulting lihtium enolate is treated with excess formaldehyde, introduced as a gas just above the surface of the stirred solution. The solution is stirred for 30 minutes at -78° and then poured into water. The aqueous phase is saturated with sodium chloride and extracted with ethyl acetate. The combined ethyl acetate solutions are dried over magnesium sulfate and filtered. The filtrate is evaporated under reduced pressure to give the crude product. Purification by chromatography on silica gel using ethyl acetate/benzene gives 8-oxo-2,2,5,7-tetramethyl-7-(hydroxymethyl)-3-oxa-1-azabicyclo[4.2.0]-octane.

Workup

additionintroduced as a gas just above the surface of the stirred solution
extractionextracted with ethyl acetate
dry with materialThe combined ethyl acetate solutions are dried over magnesium sulfate
filtrationfiltered
customThe filtrate is evaporated under reduced pressure
customto give the crude product
customPurification by chromatography on silica gel

Sources & evidence

ORD record: ord-043301bbe67d4732a927c59849f0fa93
Source dataset: uspto-grants-1980_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04232036

Reaction notes

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