A mild method for the alcoholysis of β-lactams

The Chemistry of Vicinal Diamines

“…The diamines can in principle be obtained through opening of the ring of these b-lactams. Such a process has recently been performed by Palomo et al [175] (Scheme 97). While the methanolysis of b-lactam 399, substituted with an oxazolidyl group, afforded a mixture of the syn adduct 400 and anti adduct 401, a single protected diamine 403 was obtained from 402 under similar conditions.…”

Hydrophobic Vitamin B12 Derivatives: Unprecedented Formation of a 7‐Membered Lactam

“…The addition of NaN 3 as a catalyst [12] and prolongation of the reaction time up to 3 days did not lead to any significant improvement; amide 9 was obtained in a low yield of 28 %. Palomo et al showed that NaCN is an efficient catalyst for the aminolysis reaction; [13] replacement of NaN 3 with NaCN afforded desired compound 9 in a satisfactory 85 % yield in only 24 h (Scheme 3). Following the developed procedure, lactam 8 was also treated with propargylamine and amine 12 [13] to give a yield of 68 and 44 %, respectively.…”

“…Palomo et al showed that NaCN is an efficient catalyst for the aminolysis reaction; [13] replacement of NaN 3 with NaCN afforded desired compound 9 in a satisfactory 85 % yield in only 24 h (Scheme 3). Following the developed procedure, lactam 8 was also treated with propargylamine and amine 12 [13] to give a yield of 68 and 44 %, respectively. The results show that lactam 8 could be easily opened with a variety of amines, making the rare C8-functionalized cobalamin derivatives accessible.…”

“…The use of EDC [1-ethyl-3-(3-dimethylaminopropyl)carbodiimide] gave a disappointing 56 % yield ( A common trend throughout the EDC reactions was the formation of an unknown compound, which was reflected in the low yields of amide 5. It was structurally characterized by 1 H, 13 C, COSY, HSQC, and HMBC NMR, and ESI-MS. The 1 H NMR spectra showed the presence of an additional signal at δ = 8.03 ppm and the disappearance of one methyl ester group.…”

Synthesis, hydrolysis, biochemical and theoretical evaluation of 1,4-bis(alkoxycarbonyl)azetidin-2-ones as potential elastase inhibitors

“…Accordingly, CN 2 and N 3 2 were used as catalysts for the chemoselective aminolysis or alcoholysis of N-alkoxycarbonyl azetidinones bearing a C4 ester substituent. 38 As far as basic hydrolysis is concerned, one publication reported that N-arylsulfonylazetidinones equipped with an alkoxycarbonyl substituent at C4 are hydrolyzed in phosphate buffer, 28b giving the cleavage of the b-lactam ring without ester saponi®cation. We did not identify hydrolysis studies related to our compounds 5±13 (Schemes 2 and 3).…”