A new multicomponent synthesis of 2-aminothiophene carbocyclic acids 4 by reaction of methyl 2-siloxycyclopropane-carboxylates 1, alkyl cyanoacetates, and elemental sulfur is reported. This version of the Gewald thiophene synthesis rapidly provides a new type of δ-amino acids, which can be considered as dipeptide analogues. Smooth protective-group manipulations allowed regio- and chemoselective couplings with l-phenylalanine derivatives furnishing new tripeptide analogues such as 5 and 8 or products of type 10.