(2R,5S)-2-allyl-5-(tert-butyl)-3,6-dimethoxy-2,5-dihydropyrazine

ethyl 2-acetamido-2-(ethoxycarbonyl)-4-pentenoate

ethyl 2-(acetamido)-4-pentenoate

(R)-allylglycine ethyl ester

(3R,6R)-3-methyl-1,4-di-((S)-1-phenylethyl)-6-(prop-2-enyl)piperazine-2,5-dione