Why am I getting an error for some of these reactions? Also this software does not let us use NaNH2 or BuLi. Can someone please provide the correct synthesis without nanh2 thanks.

Using reactants and reagents containing four carbons or less, propose a synthesis of the following compound. (you can choose to use the reactions in the table above if that helps) CH3 CH3 H3C CH2 H3C -BI CH3 pertanya- CH3 . Na/NH3 H3C H2 Pd CH3 KG CH3 CH3 Error CH OK CH3 OK CH3 CH3 CH3 CH3 H3C Br -; c LDA HCS ECH LDA -HC ECH CH3 CH3 OK Error OK Plus one or more additonal products