(3S,4R)-1-(t-butyldimethylsilyl)-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-4-carbomethoxymethylazetidin-2-one → (3S,4R)-1-(t-butyldimethylsilyl)-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-4-(2-oxoethyl)azetidin-2-one

HRID 355179Notes

Reaction equation

[H-].C([Al+]CC(C)C)C(C)C.[Si:11]([N:18]1[C@H:21]([CH2:22][C:23](OC)=[O:24])[C@@H:20]([C@H:27]([O:29][Si:30]([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:32])[CH3:31])[CH3:28])[C:19]1=[O:37])([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12]>C1(C)C=CC=CC=1>[Si:11]([N:18]1[C@H:21]([CH2:22][CH:23]=[O:24])[C@@H:20]([C@H:27]([O:29][Si:30]([C:33]([CH3:36])([CH3:35])[CH3:34])([CH3:31])[CH3:32])[CH3:28])[C:19]1=[O:37])([C:14]([CH3:17])([CH3:15])[CH3:16])([CH3:13])[CH3:12]

Participants

Conditions

Temperature: -78 °C

Procedure

Diisobutylaluminum hydride (3.72 ml of 0.91 M in hexane, 3.38 mmol) is added slowly by syringe to a solution of (3S, 4R)-1-(t-butyldimethylsilyl)-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-4-carbomethoxymethyl azetidin-2-one (936 mg, 2.26 mmol) in 25 ml of freshly distilled toluene at -78° C. The resulting solution is stirred at -78° C. for 3 hrs., then quenched by addition of 2.5 N hydrochloric acid (5 ml). The resulting mixture is stirred for 2 min., then poured into a separatory funnel containing 100 ml of ether and 50 ml of 1.25 N hydrochlorid acid saturated with tartaric acid. The organic phase is separated and the aqueous phase is extracted with ether (2×50 ml). The combined organic phases are washed with brine and dried over magnesium sulfate. Removal of solvents in vacuo gives a white solid which is recrystallized from ether-petroleum ether to give (3S,4R)-1-(t-butyldimethylsilyl)-3-[(R)- 1-(t-butyldimethylsilyloxy)ethyl]-4-(2-oxoethyl)-azetidin-2-one. m.p. 115°-116° C.; n.m.r. (CDCl3) δ4.1(m,l), δ4.03(m,l), δ2.7-3.2(m,3), δ1.23(d,3,J=6.4), δ1.08(s,9), δ0.9(s,9), δ0.25(s,6), δ0.1(s,6), δ9.83(t,l,J=1.4).

Workup

custom, then quenched by addition of 2.5 N hydrochloric acid (5 ml)
stirringThe resulting mixture is stirred for 2 min.
additionpoured into a separatory funnel
additioncontaining 100 ml of ether and 50 ml of 1.25 N hydrochlorid acid saturated with tartaric acid
customThe organic phase is separated
extractionthe aqueous phase is extracted with ether (2×50 ml)
washThe combined organic phases are washed with brine
dry with materialdried over magnesium sulfate
customRemoval of solvents in vacuo
customgives a white solid which
customis recrystallized from ether-petroleum ether

Sources & evidence

ORD record: ord-e821b6980d314fc8bcdb013ef480ce2d
Source dataset: uspto-grants-1983_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04378315

Reaction notes

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