Diphenylmethyl 3-[(5RS)-2,5-dihydro-2-oxofuran-5-yl methyl]-7beta-phenylacetamidoceph-3-em-4-carboxylate → Diphenylmethyl 3-[(5RS)-2-oxotetrahydrofuran-5-yl methyl]-7beta-phenylacetamidoceph-3-em-4-carboxylate

関与物質

反応手順

Diphenylmethyl 3-[(5RS)-2,5-dihydro-2-oxofuran-5-yl methyl]-7β-phenylacetamidoceph-3-em-4-carboxylate (Example 2(a)), (1.58 g) in 50% ethanol/benzene (100 mls) was treated with tris(triphenylphosphine)rhodium (I) chloride (0.75 g) and 10% palladium on carbon (0.2 g) and hydrogenated for several hours at room temperature. The reaction was monitored by t.l.c. analysis until formation of the slightly more polar product was complete. The solution was filtered through a small pad of silica gel and then concentrated. Purificationby `flash` chromatography afforded the title compound as a brown solid, (0.62 g, 39%); a sample recrystallized from ethyl acetate was shown to be a single isomer by spectroscopic analysis, m.p. 84°-89° C., νmax (KBr) 3400 (br), 3299, 1782, 1770, 1735, 1719, 1661, 1619, 1533, 1494, 1453 and 1373cm-1 ; δH (CDCl3) 1.75 (1H, m), 2.23 (2H, m), 2.43 (2H, m), 3.02 (1H, dd, J2.3, 13.8Hz), 3.52 (2H, ABq, J18.7Hz), 3.66 (2H, ABq, J16.2Hz), 4.66 (1H, m), 4.93 (1H, d, J4.7Hz), 5.87 (1H, dd, J4.7, 9.2Hz), 6.11 (1H, d, J9.2Hz), 6.84 (1H, s) and 7.25-7.5 (15H, m); [mass spectrum: +ve ion (3NOBA, Na+) MNa+ 605].

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