2-Picolyl thioesters; a useful synthon for the preparation of 1-β-alkyl carbapenem intermediates
- 1 June 1988
- journal article
- research article
- Published by Canadian Science Publishing in Canadian Journal of Chemistry
- Vol. 66 (6) , 1537-1539
- https://doi.org/10.1139/v88-248
Abstract
In this study, a highly stereoselective preparation of (3S,4S)-3-[(1R)-1-tert-butyldimethylsilyloxyethyl]-4-[(1R)-1-carboxy-ethyl]-azetidin-2-one (2) is reported. It involves a Lewis acid mediated condensation of (3S,4R)-4-acetoxy-3-[(1R)-1-tert-butyldimethylsilyloxyethyl]azetidin-2-one (3) with simple O-silylenol ethers of thiopropionates. From all the examples reported in this paper the 2-picolyl thiopropionate or similar arrangements were found to be essential for this stereoselection. Finally, a mechanism involving chelation control seems to be operative.This publication has 2 references indexed in Scilit:
- Practical preparation of 4(R)-allylazetidinones and 4(R)-(1-methylallyl)azetidinonesThe Journal of Organic Chemistry, 1985
- A simple method of preparing trimethylsilyl- and tert-butyldimethylsilyl-enol ethers of α-diazoacetoacetates and their use in the synthesis of a chiral precursor to thienamycin analogsCanadian Journal of Chemistry, 1984