Studies on Penam Sulfones. Part 3. Synthesis and β-Lactamase Inhibitory Activity of Sodium (6R)-6-(α-Hydroxybenzyl)-2β- methoxyiminomethyl-2α-methylpenam-3α-carboxylate 1,1- Dioxide and Sodium 2β-Acyl-2α-methylpenam-3α- carboxylate 1,