Line breaks reaction schemes

Figure 1 The theoretical plot of induction time of oxidation determined for wr — 0, (zero rate of initiation according to reaction 1 of Scheme 1) on composition of the mixture of inhibitors InH (chain-breaking antioxidant) and D (peroxide decomposer) having the total sum of concentrations 0.01 mol/l. The curve 2 below is the plot of induction times for the same values of parameters as for line 1 but w, = 5 x 10-8 mol/l. The initial concentration of hydroperoxides was 0.001 mol/l.

Scheme 2. Conformational changes of the y-phosphate in a) phosphoryl-transfer reaction transition state K), and various species of AlFx b) AlF41, c) A1C13. Dotted lines indicate that the degree of bond making and bond breaking determines whether the transition is more dissociative, with a metaphosphate-like intermediate, or associative, with a pentavalent intermediate. Charges have been omitted for clarity. N = adenosine or guanosine. According to [16, 17, 21]...

Other examples of this type of stereoelectronic consideration exist, in line with standard mterpretapons of such effects in polar organic reactions. But complications can arise in which the paradigm seems to break down, as in the example shown in Scheme 7.11. In this case, it was proposed that neighboring group participation resulted in a stereochemically labile species (35), leading to loss of stereochemical control.It is thus likely that rapid isomerization interfered with an otherwise mechanistically well-defined process. 

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