Thionyl Chloride → Methyl 7-Phthalimido-3alpha-methyl-3beta-hydroxycepham-4-carboxylate

Participants

Reaction Steps

A solution of methyl 6-phthalimido-2,2-dimethylpenam-3-carboxylate-1-oxide (2.25 g., 6 mmol) and thionyl chloride (0.47 ml., 6.5 mmol) in 90 ml. dry carbon tetrachloride was refluxed for 1 hour, cooled and evaporated in vacuo to dryness. An nmr spectrum of the crude product showed a 2:3:3 mixture of methyl 7-phthalimido-3α-methyl-3β-hydroxycepham-4-carboxylate, methyl 6-phthalimido-2β-chloromethylpenam-2α-methyl-3-carboxylate, and methyl 6-phthalimido-2α-chloromethylpenam-2β-methyl-3-carboxylate, respectively. The products were separated by chromatography on silica gel and fully characterized by spectroscopy.

Provenance & Evidence