Synthesis of Alaremycin

Abstract

Methyl 5-azido-4-oxohexanoate was synthesized from 5-hexenoic acid in six steps and converted to the title compound by NaReO₄- and CF₃SO₃H-catalyzed reaction in Ac₂O/CCl₄ followed by hydrolysis of the methyl ester moiety.

Key words

amides - antibiotics - azides - palladium - rhenium

References and Notes

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9

Another sequence shown below produced (α-chloro)ethyl ketone i in low yield (Scheme [2] ).

10

Acid 6 is commercially available, but was conveniently prepared from cyclohexanone in 67% yield by oxidative ring cleavage with H₂O₂, FeSO₄, and CuSO₄. [11]

13

Although the original procedure [12] uses PEG-2000 as an additive, the reaction in H₂O was found to be quite successful.