Ammonium Chloride → (3aR,5S,6aR)-2,2-dimethyl-5-[(2R)-oxiran-2-yl]-3a,5,6,6a-tetrahydrofuro[2,3-d][1,3]dioxole

HRID 60696Notes

Reaction equation

CC1C=CC(S(O[CH2:12][C@H:13]([C@H:15]2[O:24][C@@H:18]3[O:19][C:20]([CH3:23])([CH3:22])[O:21][C@@H:17]3[CH2:16]2)[OH:14])(=O)=O)=CC=1.C[Si]([N-][Si](C)(C)C)(C)C.[K+].[NH4+].[Cl-]>C1COCC1>[CH3:22][C:20]1([CH3:23])[O:19][C@H:18]2[O:24][C@H:15]([C@H:13]3[CH2:12][O:14]3)[CH2:16][C@H:17]2[O:21]1

Participants

Conditions

Temperature: -70 °C

Procedure

To a solution of [(2R)-2-[(3aR,5S,6aR)-2,2-dimethyl-3a,5,6,6a-tetrahydrofuro[2,3-d][1,3]dioxol-5-yl]-2-hydroxy-ethyl] 4-methylbenzenesulfonate (compound 6a, 100 g, 280 mmol) in anhydrous THF (1500 mL) cooled at −70° C. was added potassium bis(trimethylsilyl)amide (340 mL, 340 mmol, 1 M in THF) under N2 atmosphere. After being stirred at −70° C. for 1 hour, the reaction mixture was poured into saturated NH4Cl solution. The organic layer was separated and the aqueous phase was extracted with EtOAc. The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 1:3 EtOAc in petroleum ether) to afford 40.5 g of (3aR,5S,6aR)-2,2-dimethyl-5-[(2R)-oxiran-2-yl]-3a,5,6,6a-tetrahydrofuro[2,3-d][1,3]dioxole (compound 6b) as a slight yellow oil.

Workup

customThe organic layer was separated
extractionthe aqueous phase was extracted with EtOAc
dry with materialThe combined organic layers were dried over Na2SO4
concentrationconcentrated in vacuo
customThe residue was purified by column chromatography on silica gel (eluting with 1:3 EtOAc in petroleum ether)

Sources & evidence

ORD record: ord-0bac61f13d1a47729c73cbeecbe5f4b7
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09441008B2

Reaction notes

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