N,N'-bis[(phenylmethoxy)carbonyl]bis[L-valine], O,O'-[(1S,2R,3R)-3-(2-amino-6-oxo-1H-purin-9-yl)cyclobuta-1,2-diyl]methyl ester

trans-3,3-diethoxy-1,2-cyclobutanedicarboxylic acid

trans-3,3-diethoxy-1,2-cyclobutanedicarboxylic acid diethyl ester

[1S-[1α(S*),2β(S*)]]-N,N'-Bis[2-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-1-phenylethyl]-3,3-diethoxy-1,2-cyclobutanedicarboxamide

[1S-[1α(S*),2β(S*)]]-N,N'-Bis[2-[[(1,1-dimethylethyl) dimethylsilyl]oxy]-1-phenylethyl]-3,3-diethoxy-N,N'-dinitroso-1,2-cyclobutanedicarboxamide