5776-62-5Relevant academic research and scientific papers
Importance of the C(3) Substituent of the Penam Derivative in Interconversion Reactions of Penam and Cepham Systems
Balsamo, Aldo,Benedini, Paola Maria,Macchia, Bruno,Macchia, Franco,Rossello, Armando
, p. 413 - 417 (1984)
The azetidinone disulphide (1b), a structural analogue of Kamiya's disulphide (1a), has been synthesized.Some cyclization reactions of the disulphides (1) (Br2 in CH2Cl2 and AcOAg in ClCH2CO2H-CH2Cl2) leading to penal and cepham derivatives through episulphonium ions (2), have been studies.The data obtained show that changing the substituent X in (1a) and (1b) brings about changes in the distribution of the positive charge in the intermediate episulphonium ions (2a) and (2b), and thus affects to some extent the regioselectivity of the episulphonium ring opening and the chemical behaviour of (1a) and (1b).
The Roles of the Carboxy Group in β-Lactam Antibiotics and Lysine 234 in β-Lactamase I
Laws, Andrew P.,Layland, Nicola J.,Proctor, David G.,Page, Michael I.
, p. 17 - 21 (2007/10/02)
The replacement of the C3 carboxylate in phenoxymethylpenicillin by a hydroxymethyl group and of the C4 carboxylate in cephalosporins by both a lactone and an aldehyde gives derivatives which are still good substrates for Bacillus cereus 569/H β-lactamase
