The enantiomers (up to 99% ee) of both geraniol- and nerol-derived 2-cyclohexyl-5,9-dimethyldeca-4,8-dienoic acid, the active ingredient of the wound healing medication Cygerol, were prepared via a low-temperature alkylation, basic hydrolysis, derivatization with (S)-4-benzyloxazolidin-2-one and chromatographic separation steps. The absolute configuration of stereocenters in the antipodes having an (E)- or (Z)-geometry of the internal double bond was determined based on characteristic 1H NMR signals of the corresponding (S)-4-benzyloxazolidin-2-one-derived imides and on conversion to the known diethyl (S)-2-cyclohexylsuccinate and (S)-2-cyclohexylbutane-1,4-diol with reported specific rotations. 相似文献
The carbonyl cobalt complex Cp*Co(CO)I2 catalyzes carbenoid Co alkylation of N-(pyrimidin-2-yl)indole with methyl 3,3,3-trifluoro-2-diazopropionate regioselectively giving 2-substituted indole, while the N,N’-ligated cations [CpCo(L)I]+ (L = bipy, phen) provide 3-substitution exclusively. The structure of [CpCo(phen)I]PF6 was investigated by X-ray diffraction.
