Diisopropylamine → 2-[(1,1-Dimethylethoxy)carbonyl]amino-3-phenylmethoxy-4pentenoic acid

Beteiligte Stoffe

Reaktionsschritte

A lithium diisopropylamide solution (37.3 M) is prepared from N,N-diisopropylamine (5.2 mL, 37.2 mmol) in THF (30 mL. cooled to −20° C.) and 3.7 mL (37.3 mmol) 10 M n-BuLi in hexane. The LDA solution in THF is added to a stirred solution of N-[(1,1-dimethylethoxy)carbonyl]glycine-4-phenylmethoxy-2-butenyl ester 63a (14.9 mmol) and ZnCl2 (17.9 mmol) in 100 mL THF at −78° C. The mixture is allowed to come to room temperature overnight. The crude mixture is partitioned between 700 mL ethyl acetate and 700 mL 1 N HCl. The organic layer is washed with 150 mL dilute NaHCO3 solution (3×'s). The bicarbonate washes are acidified with conc. HCl to pH1 and extracted with 700 mL ethyl acetate. The ethyl acetate layer is dried over magnesium sulfate and the solvent removed in vacuo to give the named compound.

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