23934-75-0Relevant academic research and scientific papers
Synthesis of (1′R,3S,4S)-3-[1′-(tert-butyldimethylsilyloxy) ethyl]-4-(cyclopropylcarbonyloxy)azetidin-2-one
Laurent, Mathieu,Ceresiat, Marcel,Marchand-Brynaert, Jacqueline
, p. 3755 - 3766 (2007/10/03)
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.
Preparation of (3S,4S)-1-benzhydryl-3-[(5R)-1'-hydroxyethyl]-4-acyl-2- azetidinones from (2R,3R)-epoxybutyramide precursors
Deng, Bo-Liang,Demillequand, Marc,Laurent, Mathieu,Touillaux, Roland,Belmans, Marc,Kemps, Luc,Cérésiat, Marcel,Marchand-Brynaert, Jacqueline
, p. 3209 - 3217 (2007/10/03)
The N-(phenacyl)-8a and N-(pivaloylmethyl)-8b derivatives of N- (benzhydryl)-(2R,3R)-cis-2,3-epoxybutyramide were prepared from sodium (2R,3R)-cis-2,3-epoxybutanoate 4. Under basic conditions they gave S(N)i reactions leading to the formation of four-, si
