| 摘要 |
Acetoxymethylpenam dioxides I (R=H, 3-phthalidyl, 4-crotonolactonyl, γ-butyrolacton-4yl, α-acyloxyalkyl) were prepd. Thus, benzyl 6,6-dibromo-2,2-dimethyl-(5R)-penam-3α-carboxylate was oxidized to the 1-oxide which was hydrogenated over pd-C to give benzyl 2,2-dimethyl-(5R)-penam-3α-carboxylate 1α-oxide. The latter compd. was heated with AC2O to give benzyl 2β-acetoxymethyl-2α-methyl-(5R)-peham-3α-carboxylate, which was oxidized to the 1,1-dioxide I (R=CH2P).
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