Substituted carbonic acid esters

Compounds having the formula:

• ##STR13## wherein, Ad is the 1-adamantyl residue which is unsubstituted or substituted by alkyl groups of 1 to 8 carbon atoms, alkoxy groups of 1 to 8 carbon atoms, nitro groups, or halogen,
• R.sup.1 and R.sup.2 are saturated alkyl groups of 1 to 8 carbon atoms;
• and
• X is chlorine;
• fluorine;
• azido, phenoxy;
• phenoxy substituted in the benzene nucleus by fluorine, chlorine, bromine, iodine, nitro, alkoxy groups, or alkyl groups;
• N-oxysuccinimido;
• or residues having the formulae:
• ##STR14## wherein Ad has the above-identified meaning.