. . . . "Typical examples of R and R1 are methyl, ethyl, propyl, i-propyl, butyl, i-butyl, sec-butyl, t-butyl, amyl, i-amyl, sec-amyl, t-amyl, neopentyl, hexyl, t-hexyl, n-octyl, t-octyl, n-nonyl, n-decyl, n-dodecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, perhydronaphthyl, adamantyl, bicyclo[2.2.1]heptyl, benzyl, ??-cumyl, 2-(??-naphthyl)ethyl, ??-methyl-??-ethylbenzyl," .