Cyclopentane derivatives

Abstract

Novel cyclopentane derivatives which are useful as an intermediate for the preparation of N-(L-aspartyl)-N'-(2,2,5,5-tetramethylcyclopetanecarbonyl)-R-1,1-diaminoet hane are represented by the formula (I) ##STR1## wherein R.sub.1 is hydrogen and R.sub.2 is cyano, formyl, carbamoyl, alkanesulfonyloxy, or ##STR2## wherein R.sub.3 and R.sub.4 are the same or different and represent alkyl, substituted alkyl or R.sub.1 and R.sub.2 are combined to be methylsulfinylmethylene, acetoxymethylthiomethylene, halomethylthiomethylene, methylthiomethylene, alkoxymethylene, or --CH.sub.2 --O--.

Dependencies are inferred from the claim text.