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DOI: 10.1055/sos-SD-021-00567

Coates, C.; Kabir, J.; Turos, E.Science of Synthesis, (200521612.

The acid chlorides most commonly used in the synthesis of β-lactams are azidoacetyl chloride (15) and the protected hydroxyacetyl chloride 18. The reaction of the former reagent with an imine is known as the Bose reaction and allows for the introduction of a latent amino group at the C3 position of the β-lactam ring, e.g. formation of β-lactams 16A and 16B (Scheme 5).[‌12‌] The only limitation to the Bose reaction is that it is unsuitable for large-scale preparations because of the potentially explosive decomposition of azidoacetic acid and its derivatives.[‌13‌] Reaction of a protected hydroxyacetyl chloride, e.g. 17, with imines such as 18, allows for the introduction of a C3 hydroxy group, upon removal of the protecting group, onto the β-lactam, e.g. the synthesis of 3-acetoxy derivative 19 (Scheme 6). The protecting groups used include acetoxy, benzyl, and trialkylsilyl, which can be easily removed under standard conditions. The corresponding β-lactams are versatile synthons for penicillins and α-hydroxy-β-amino acids.

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