1-β-Methylcarbapenem intermediates. Stereoselective synthesis of (3S,4R)-3-[(1R)-1-tert-butyldimethylsilyloxyethyl]-4-[(1R)-3-methoxycarbonyl-1-methyl-2-oxopropyl]azetidin-2-one and its related chemistry
The reaction of silyl enol ethers with phthaloyl dichloride afforded alkylidene-3-oxo-3H-isobenzofurans with very good E/Z-selectivity. cyclizations - O-heterocycles - phthalic acid derivatives - silyl enol ethers