| abstract |
What are disclosed are compounds, useful as intermediates in the preparation of substituted penem compounds, of the formula ##STR1## wherein R is a removable esterifying group, R 2 is hydrogen, lower alkyl, lower alkoxyalkyl, lower alkanoyloxyalkyl, or tri-lower alkylsilyloxyalkyl, and R a , R b , R c , R d , and R e are hydrogen, aliphatic cycloaliphatic hydrocarbon, free or esterified carboxyl, halo, or cyano, and any two of R a -R e , taken together, may form a cycloaliphatic ring. |