(5R)-5-ethyl-5-((S)-2-(methoxymethyl)pyrrolidine-1-carbonyl)-6-(trimethylsilyl)oxepan-2-one

2-ethyl-2-(3-hydroxypropyl)-4-butanolide

(S)-3-(3-ethyl-2-oxotetrahydrofuran-3-yl)propanoic acid

(S,E)-3-ethyl-3-(2-nitrovinyl)tetrahydro-2H-pyran-2-one