Synthesis of (1 ' R,3S,4S)-3-[1 '-(tert-butyldimethylsilyloxy)ethyl]-4-(cyclopropylcarbonyloxy)azetidin-2-one
(2006) European Journal of Organic Chemistry — n° 16, p. 3755-3766 (2006)
Files
No attached file found for this publication.
Details
- Authors
- Abstract
- 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 (Be). This key intermediate gave a regio- and stereoselective C3-C4 ring closure on LiHMDS treatment in THF at 0 degrees 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 le (title compound). ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
- Affiliations
Tessenderlo Chem SA Brussels, Belgium
Citations
Laurent, M., Ceresiat, M., & Marchand-Brynaert, J. (2006). Synthesis of (1 ′ R,3S,4S)-3-[1 ’-(tert-butyldimethylsilyloxy)ethyl]-4-(cyclopropylcarbonyloxy)azetidin-2-one. European Journal of Organic Chemistry, 16, 3755-3766. https://doi.org/10.1002/ejoc.200600235 (Original work published 2006)