(R)-2-Vinylcyclopropan-1,1-dicarbonsaeure

[(1SR,2Ξ)-2-Methyl-3-oxocyclopentyl]essigsaeure-methylester

(R)-(+)-2-Vinyl-1,1-cyclopropandicarbonsaeure-dimethylester

[(6ω,7S)-6-Methyl-1,4-dioxaspiro[4,4]non-7-yl]essigsaeure-methylester

(1R)-2c-methoxycarbonylmethyl-1-methyl-5-oxo-1r-cyclopentancarbonsaeure-methylester