94944-11-3

Upstream product

• 94944-07-7 (3S,4S,1'R) N-p-methoxyphenyl-3-(1'-hydroxyethyl)-4-benzoylazetidin-2-one 
• 118990-84-4 (3S,4R)-4-benzoyl-3-<1(S)-<(triisopropylsilyl)oxy>ethyl>-1-(p-methoxyphenyl)azetidin-2-one 
• 62558-62-7 (E)-2-((4-methoxyphenyl)imino)-1-phenylethanone 
• 1074-12-0 phenylglyoxal hydrate 
• 475062-52-3 (3S,4S,5R)-N-diphenylhydroxymethyl-3-(1'-hydroxyethyl)-4-benzoylazetidin-2-one 
• 283176-71-6 (3S,4S,5R)-1-benzhydryl-3-(1'-hydroxyethyl)-4-benzoyl-2-azetidinone 
• 283176-70-5 N-(benzhydryl)-N-(phenacyl) (2R,3R)-cis-2,3-epoxybutyramide 
• 70-11-1 α-bromoacetophenone 
• 23934-75-0 2-(benzhydrylamino)-1-phenyl-1-ethanone 
• 104401-70-9 (3S,4S)-4-benzoyl-3-<1-(R)-hydroxyethyl>-2-azetidinone 

Relevant academic research and scientific papers

Synthesis of (1′R,3S,4S)-3-[1′-(tert-butyldimethylsilyloxy) ethyl]-4-(cyclopropylcarbonyloxy)azetidin-2-one

The novel carbapenem precursor 1e has been synthesized from L-threonine, cyclopropyl methyl ketone and benzhydrylamine (for the introduction of the azetidinone N-protecting group). Two independently prepared building blocks - sodium (2R,3R)-2,3-epoxybutyrate as a mixed salt with NaBr (2b) and N-(benzhydryl)aminomethyl cyclopropyl ketone (4e) - were coupled to give (2R,3R)-N-(benzhydryl)-N-(2-cyclopropyl-2-oxoethyl)-2,3-epoxybutyramide (8e). This key intermediate gave a regio- and stereoselective C3-C4 ring closure on LiHMDS treatment in THF at 0°C to yield (1′R,3S,4S)-4- cyclopropylcarbonyl-1-diphenylmethyl-3-(1-hydroxyethyl)azetidin-2-one (13e). N-Deprotection of 13e was performed by photochemical bromination and subsequent hydrolysis. The resulting (1′R,3S,4S)-4-(cyclopropylcarbonyl)-3-(1- hydroxyethyl)azetidin-2-one (23e) reacted in a Baeyer-Villiger oxidation with a total control of the regioselectivity (due to the poor migratory aptitude of the cyclopropyl group) to furnish (1′R,3S,4S)-3-(1-hydroxyethyl)-4- (cyclopropylcarbonyloxy)azetidin-2-one (24e), subsequent O-silylation achieving the total synthesis of 1e (title compound). Wiley-VCH Verlag GmbH & Co. KGaA, 2006.

Oxidation process for preparing 4-acyloxy azetidinones in a two-phase system

Process for preparing compounds according to formula (I) STR1 wherein R1 and R2 represent a hydrogen atom or a protective group and R3 represents a C1 -C10 alkyl or an aryl group, by oxidation of compounds according to formula (II) STR2 wherein R1, R2 and R3 have the above-mentioned meanings, in a two-phase system comprising: a) an organic phase including a 4-acylazetidinone compound (II) and an "onium" salt dissolved in a medium immiscible with water, b) an aqueous solution including an alkali or alkaline-earth metal salt of an organic or inorganic peracid. 4-Acyloxyazetidinones (I) are useful intermediates in the synthesis of anti-bacterial compounds.

OXIDATION OF A 4-BENZOYL-2-AZETIDINONE BY POTASSIUM PEROXOMONOSULFATE

KHSO5 oxidizes the ketone I to the corresponding benzoate II in satisfactory yield, under very mild conditions.No oxidation of the alcoholic group was detected.