A novel synthesis of the monobactam antibiotic carumonam

Conversion of Aziridinemethanol Sulfonate Esters to Allylic Amines via Tellurium Chemistry1

“…The tert -butyldimethylsilyl ether of ethyl (2 S ,3 S )-1-( tert -butyloxycarbonyl)-α-hydroxyaziridinemethane-3-carboxylate was prepared in the same way as the 2 R ,3 R methyl ester 19f. Ethyl (2 R ,3 S )-α-hydroxyoxiranemethane-2- carboxylate (2.91 g, 19.9 mmol) yielded the aziridinemethanol as a yellow liquid (1.94 g, 7.49 mmol, 53%): [α] 21.5 D + 46.4 ( c 1.02, CHCl 3 ); 1 H NMR δ 0.08 (s, 6 H), 0.8 (s, 9 H), 1.3 (t, 3 H, J = 7.1), 1.7 (br s, 1 H), 2.4 (br s, 2 H), 3.6 (br m, 2 H), 4.2 (m, 2 H) [lit 19f. ( R , R )-methyl ester: 1 H NMR δ 0.05 (s, 6 H), 0.9 (s, 9 H), 1.3 (br s, 1 H), 2.4 (br s, 2 H) 3.7−3.5 (m, 2 H), 3.7 (s, 3 H)]; 13 C NMR δ −5.3, 14.1, 18.3, 25.8, 33.5, 40.0, 61.5, 64.7, 172.5 [lit 19f.…”

Approach to Monobactams and Nocardicins via Diastereoselective Kinugasa Reaction

“…The opening of the six-membered ring and deprotection of the β-lactam nitrogen atom were expected to provide an entry to a variety of monocyclic β-lactams. Particularly interesting are alkyne 15 and nitrones 7 – 10 since their combination should provide an entry to nocardicins 16 and monobactams such as aztreonam 17 and carumonam 18 …”

An Enantioselective Synthesis of (2S,3R)-3-(N-Benzyloxycarbonyl)amino-1-chloro-4-phenylthiobutan-2-ol, a Central Intermediate of Nelfinavir1

“…Stereoselective Introduction of the Amine Function. After mild saponification of 8 , the resulting sodium carboxylate was treated directly with aqueous ammonia, according to the same procedures as reported by Manchand et al., to give the dihydroxy α-amino acid as its sodium salt 12a in a reproducible way (Scheme ) . It was then subjected to the biphasic Schotten−Bauman conditions to form a benzyl carbamate.…”