diethyl 2-hydroxycyclohexane-1,1-dicarboxylate
diethyl 2-cyclohexene-1,1-dicarboxylate
(S)-1-ethoxycarbonyl-2-cyclohexene-1-isocyanate
(R)-1-ethoxycarbonyl-2-cyclohexene-1-carboxylic acid
(S)-ethyl 1-benzyloxycarbonylamino-2-cyclohexene-1-isocyanate