On production of D* and D in B-meson decays

B→D*ev and B→Dev decays are considered. In a certain theoretical limit, the probability of decays of such a type is shown to be unambiguously calculable, and these two decay channels exactly saturate the semileptonic decay width. It is argued that actual B and D mesons are in fact not far from this limit. Furthermore, the rate B→D*ev for slow D* mesons is calculated with the expected accuracy of the order of 10%. Total branching ratios of B→D*ev and B→Dev are estimated within a factor of 1.5 to be, respectively, ∼ 8% and ∼ 2%. The approach can also be used for a rough estimate of nonleptonic decay rates of B mesons involving D or D* in the final state