In the previous sections the various possibilities for the production of 19-norsteroids from 19-substituted compounds have been reviewed. It is virtually impossible to compare the efficiency of the various procedures since optimal conditions are usually not described. [Pg.278]

More generally, without considermg the various possible kinds of work, one can write for an isothennal change in a closed system (dn. = 0) [Pg.347]

The information obtained by this preliminary analysis can be used not only to set priorities for the various possible Diels-Alder disconnections, but also to pinpoint obstacles to transform application. Recognition of such obstacles can also serve to guide the search for specific retrosynthetic sequences or for the highest priority disconnections. At this point it is likely that [Pg.18]

The activation of halothiazoles toward nucleophilic displacement is discussed in Chapter V no unique conclusion can be drawn because of the various possible interactions between the halothiazole base and the electrophilic counterpart of the nucleophile. [Pg.147]

Fig. 3.44 Example of the range deperident behavior of rule T20 the system evolves as class-2 for r=l, class-4 for r = 2 and class-3 for r 3. The various possible intermediate (or transitional) behaviors can be studied by successively applying we.ll-defined minimal topological deformations to the initial lattice. |

For any given value of T, equation (1) gives on solution at least one value of p. If we put x — T, y = p, the assemblage of points representing the various possible solutions of (1) constitute a curve which is called the saturation curve. [Pg.210]

Figure 13. Voltage relaxation method for the determination of the diffusion coefficients (mobilities) of electrons and holes in solid electrolytes. The various possibilities for calculating the diffusion coefficients and from the behavior over short (t L2 /De ) and long (/ L2 /Dc ll ) times are indicated cc h is the concentration of the electrons and holes respectively, q is the elementary charge, k is the Boltzmann constant and T is the absolute temperature. |

Enamines derived from 1-azabicycloalkanes, readily accessible by mercuric acetate oxidation of saturated bases (112), have been extensively studied recently (113-115). Since an immonium salt is formed during dehydrogenation, the composition of the liberated enamine mixture shows the relative stability of the various possible isomers. The study of infrared and NMR spectra has shown that the position of the enamine double bond is determined by factors similar to those determining the relative stability of simple olefins. [Pg.267]

In general, a point group synnnetry operation is defined as a rotation or reflection of a macroscopic object such that, after the operation has been carried out, the object looks the same as it did originally. The macroscopic objects we consider here are models of molecules in their equilibrium configuration we could also consider idealized objects such as cubes, pyramids, spheres, cones, tetraliedra etc. in order to define the various possible point groups. [Pg.145]

In analyzing the behavior of these types of tetrahedral intermediates, it should be kept in mind that proton-transfer reactions are usually fast relative to other steps. This circumstance permits the possibility that a minor species in equilibrium with the major species may be the major intermediate. Detailed studies of kinetics, solvent isotope effects, and the nature of catalysis are the best tools for investigating the various possibilities. [Pg.481]

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