(2R)-2-ethyl-2-methylbutanedioic acid

(R)-(+)-2-Ethyl-2-methyl-3-methoxycarbonylpropionic Acid

(R)-3-methyl-3-vinyl-4-pentyn-1-ol

(R)-4-methyl-4-vinyl-5-hexynonitrile

(S)-4-{5-[(R)-3-Cyano-1-((R)-2-methoxycarbonyl-1-nitromethyl-ethyl)-1-methyl-propyl]-isoxazol-3-yl}-5,5-dimethyl-hept-6-ynoic acid methyl ester