Ester-imine condensations : Preparation of racemic intermediates for the synthesis of the carbapenem antibiotics PS-5 and PS-6.
- 1 January 1987
- journal article
- research article
- Published by Japan Antibiotics Research Association in The Journal of Antibiotics
- Vol. 40 (3) , 309-319
- https://doi.org/10.7164/antibiotics.40.309
Abstract
The lithium enolates of ethyl butyrate (7) and ethyl isovalerate (19) react with N-p-methoxyphenylcinnamaldimine (8) in tetrahydrofuran (THF)-hexamethylphosphoric triamide (HMPA) to afford predominantly trans .beta.-lactams 9 (67%) and 20 (78%), respectively. .beta.-Lactam 9 was converted to PS-5(5) intermediate 18 in 21% overall yield (8 steps). .beta.-Lactam 20 was converted to PS-6(6) analog 28 in 22% overall yield using an eight step sequence.This publication has 4 references indexed in Scilit:
- N-Trimethylsilylimines: applications to the syntheses of .beta.-lactamsJournal of the American Chemical Society, 1984
- Oxidative N-dearylation of 2-azetidinones. p-Anisidine as a source of azetidinone nitrogenThe Journal of Organic Chemistry, 1982
- A short and stereoselective synthesis of the carbapenem antibiotic PS-5Journal of the Chemical Society, Perkin Transactions 1, 1981
- Structure and stereochemistry of antibiotic PS-5.The Journal of Antibiotics, 1980