The development of a new convertible isocyanide, indole-isocyanide, for ready access to pyroglutamic acids culminated in the formal total synthesis of the proteasome inhibitor omuralide featuring a stereocontrolled Ugi reaction. Indole-isocyanide was named after the facilitation of hydrolysis of the resulting 2-(2,2-dimethoxyethyl)anilide via an N-acylindole intermediate obtained by the Ugi multicomponent condensation reaction followed by the indole formation.