(S)-5-allyl-4-tert-butoxycarbonyl-1-(2,4-dimethoxybenzyl)-2-piperazinone

1(S),5(S)-1-benzyl-8-tert-butoxycarbonyl-3-(2,4-dimethoxybenzyl)-3,8-diaza-2-oxobicyclo[3.2.1]octane

5(S),3(S)-3-benzyl-4-tert-butoxycarbonyl-1-(2,4-dimethoxybenzyl)-5-(2-oxoethyl)-2-piperazinone

1(R),5(S)-8-[1-(4-cyano-3-fluorobenzyl)-5-imidazolylmethyl]-3-(2,4-dimethoxybenzyl)-3,8-diaza-2-oxobicyclo[3.2.1]octane

(1S)-tert-butyl-1-{[(chloroacetyl)(2,4-dimethoxybenzyl)amino]-methyl}but-3-enylcarbamate