7-substituted oxa- or azasteroid compound

7-Substituted-2-oxa-7-azabicyclo [3.2.0.]heptan-6-one compound a

7-Substituted-ureido-3-carbamoyloxymethyl cephalosporin antibiot

7-[.alpha.-(2,3-DIHYDRO-2-OXO-1H-benzimidazol-1-ylcarbonyl-amino

7-[2-(2-Aminooxazol-4-yl)-2-(oximino)acetamido cephalosporin ant

7-[2-[(Substituted benzoyl)amino]acetamido]cephalosporins

7.alpha.-(.xi.-aminoalkyl)-estratrienes, process for their produ

7.beta.-(substituted)amino-3-substituted cephalosporanic acids a

7.beta.-Arylalkyl-3-methoxy or 3-hydroxy-4,5.alpha.-epoxy-6.beta

7.beta.-Arylalkyl-6.alpha., 7 .alpha.-oxymethylene-3-methoxy or

7.beta.-Arylalkyl-7.alpha.-methyl-6-oxo or 6.alpha.-hydroxy-3-me

7.beta.-substituted-4-aza-5.alpha.-androstan-3-ones as 5.alpha.-

7.beta.-[2-Etherified oximino-2-(phenyl or naphthylacetamido)]ce

7a-alkoxy-4H-pyrano[3,2-d]-oxazol-2(3H)-one and...