Name of the following compound is :
A tetrapepetide has – COOH on Alanine. This produces glycine(Gly), Valine(Val), Phenyl alanine(Phe) and Alanine(Ala, on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary sturctures) with – NH2 group attached to a chiral centre is ___