79349-56-7

Upstream product

• 146514-35-4 (RS)-N-tert-butoxycarbonyl-α-amino-γ-butyrolactone 
• 24424-99-5 di-tert-butyl dicarbonate 
• 38308-92-8 2-(tert-butoxycarbonylamino)-4-hydroxy-butanoic acid 
• 908093-98-1 diazodiphenylmethane 

Relevant academic research and scientific papers

Cyclic hydroxamates, especially multiply substituted [1,2]oxazinan-3-ones

Routes to putative N-acyl-D-ala-D-ala surrogates, beginning with the conversion of 4-, 5-, and 6-membered lactones into 5-, 6-, and 7-membered cyclic hydroxamates, are reported. The key step of the synthesis is trimethylaluminium-promoted cyclization of an ω-aminooxyester. The 7-membered cyclic hydroxamate crystallizes in a chair conformation. Extension of the reaction sequence to homoserine or homoserine lactone leads to cyclocanaline and N-acylated cyclocanalines. The 4-phenylacetamido derivative of cyclocanaline crystallizes in a boat conformation. The attachment of a 2-carboxypropyl substituent to the ring nitrogen of a 4-acylaminocyclocanaline has been effected, prior to cyclization, by coupling of the acyclic aminooxyester precursor to the triflate of benzyl lactate or, after cyclization, by coupling to tert-butyl α-bromopropionate in the presence of potassium fluoride - alumina, followed by removal of the protecting group in each case. A six-membered homolog of the antibiotic lactivicin has been synthesized by the reaction of 4-phenylacetamidocyclocanaline with benzyl 2-oxoglutarate in the presence of carbodiimide, followed by hydrogenolysis. Starting with methyl 2,4-dibromo-2,4-dideoxy-L-erythronate, which is available in two steps from L-ascorbic acid, these reaction sequences have been applied to the stereospecific synthesis of a D-alanine derivative whose nitrogen atom is enclosed within a 3,4-disubstituted [1,2]oxazinan-3-one.

Cephalosporin derivatives

This is a class of antibacterial compounds of the formula: STR1 wherein Y is straight or branched alkyl or alkenyl chain, cycloalkanomethyl of 3-6 carbon atoms, each group being optionally substituted by halogen, or a group STR2 wherein n is 0 or an integer of 1-3, A is a group --COR3 wherein R3 is hydroxy, a group STR3 wherein R4 and R5, which may be the same or different, are hydrogen or alkyl of 1-5 carbon atoms, a group STR4 or a 5- or 6-membered heterocyclic group containing nitrogen and/or sulfur, and R1 and R2, which may be the same or different, are hydrogen, alkyl of 1-5 carbon atoms, or R1 and R2 may be combined together to form cycloalkylidene of 3-5 carbon atoms, and Z is a group of the formula: STR5 wherein m is 0 or an integer of 3-5, R6 is hydrogen or alkyl of 1-3 carbon atoms, and R7, when m is an integer of 3-5, is alkyl of 1-5 carbon atoms, alkenyl, cyclopropyl, a group --(CH2)p B wherein p is 0 or an integer of 1-3 and B is amino, alkyl-substituted amino, hydroxy, carboxy, carbamoyl, trifluoromethyl, sulfonic acid, sulfonic acid amide, alkylthio or cyano or, when m is 0, is alkyl of 1-5 carbon atoms, which may optionally be substituted by halogen, alkenyl, a group STR6 wherein R8 is hydrogen, alkyl of 1-4 carbon atoms or phenyl, or cyclopropyl, and a salt thereof.