Factors That Determine the Stereoselectivity

Secondly, the optical yield of the product depends on the molar ratio of the metal ion to the 1,4-dihydropyridine derivative but not on the concentration of the metal ion. Ohnishi et al. (1976c) 

A much more interesting feature of the present system is the dependence of the optical yield on the conversion of the reduction. The first report on this phenomenon (Ohno et al. 1978b) revealed 

Moreover, it should be noticed that the configuration of the product 

Dependence of optical yield on the reaction period and molar ratio of the starting materials. 

A striking dependence of the optical yield on the conversion has also been observed in other systems. Makino et al. (1980) reported that, in the reduction of ethyl benzoylformate with PNGH, the optical yield of ethyl 5-mandelate increases as the reaction proceeds (Table 9). 

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Analyze the following data on the product ratios obtained in the epoxidation of 3-substituted cyclohexenes by dimethyldioxirane. What are the principal factors that determine the stereoselectivity ... 

Analyze the factors that determine the stereoselectivity of the addition of organometallic compounds to the following ketones. Predict the stereochemistry of the major product. 

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