Lactam analogues

Borzilleri RM, Zheng X, Schmidt RJ, Johnson JA, Kim S-H, DiMarco JD, Fairchild CR, Gougoutas JZ, Lee FYF, Long BH, Vite GD. (2000) A novel application of a pd(0)-catalyzed nucleophilic substitution reaction to the regio- and stereoselective synthesis of lactam analogues of the epothilone natural products. J Am Chem Soc 122 8890-8897. 

Desiraju et at. have prepared some mono and bicyclic-l,3-diazetidine-2-ones with a view to study them as aza analogues of /3-lactams and to evaluate their biological activities. The X-ray structure of azacarbapenam 35 and azacarbacepham 36 suggests is that the structural requirement for the biological activities of /3-lactams is met. Aza-/3-lactam analogue 37 was also crystallized and an X-ray analysis was carried out <1998J(P1)2597>. Only limited X-ray studies have been reported for aza-/3-lactams. 

Oda et al. have reported several reactions of 1,2-diazetidinones at the ring nitrogen atom in order to make aza-,8-lactam analogues <1996H(42)577>. 

Table 8 Second-order rate constants for hydroxide ion hydrolysis of /3-sultam and /3-lactam analogues...

This synthesis leads to the production of new (3-lactam analogues with the potential for exhibiting antibiotic activity and supplies useful intermediates in the synthesis of bicyclic (3-lactam antibiotics it also demonstrates the versatility of ozonolysis workup leading to the preferential selection of desired products. 

Recently, a modified approach to the Freidinger lactam analogue was reported, using a novel variant of the Fukuyama-Mitsunobu process [127]. The most salient features of the new method are its simplicity and its versatility [128, 129[. The concept is not restricted to six- or seven-membered rings [130, 131]. 

In a similar manner the synthesis of y-lactam analogues of penems (316) from A -benzyloxy-carbonyl-L-aspartic semi-aldehyde benzyl ester (315) has been described (Scheme 57) <86TL346l, 89T4537>. 

In the sulfur series oxidation of the thiol (52) with aqueous iodine produced the sulfur lactam analogue (53) (Scheme 12) <90JOC4156>. 

The pyrrolidine 235, a (25,35)-dihydroxy-(45)-amino acid moiety of the gastroprotective substance AI-77B, was prepared from the known alkene 234 in several steps. The same starting alkene also provided a lactam analogue of 235, namely 236, also a component of A1-77B (Scheme 17). ... 

Brasholz, M., Luan, X.S. and Reissig, H.U. (2005) Towards the rubromycins an efficient synthesis of a suitable isocoumarin precursor, its lactam analogue, and palladium-catalyzed couplings. Synthesis, 3571-80. 

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