13023-70-6Relevant articles and documents
A Critical Test of the Theory of Stereoelectronic Control
Perrin, Charles L.,Arrhenius, Gloria Meichia L.
, p. 2839 - 2842 (1982)
According to Deslongchamps' theory of stereoelectronic control, preferential cleavage of a tetrahedral intermediate occurs when there are two lone pairs antiperiplanar to the leaving group.However, it is concluded that the experimental evidence is ambiguous, because it requires an unreasonable assumption regarding rates of ring inversion and because there is a simpler explanation for the observations.Nevertheless, the theory is a plausible one, deserving unambiguous evidence to support it.The hydrolysis of cyclic amidines (4), via the hemiorthoamide (5), can provide a suitable test.It is observed that 2-amino-1-pyrroline (4, n = 5) and "2-iminopiperidine" (4, n = 6) hydrolyze in base solely to the amino amide (6), which is converted under the reaction conditions to the thermodynamically more stable lactam (7).This result is the first unambiguous evidence for stereoelectronic control, and it also shows that cleavage of the intermediate (5) is fast compared to nitrogen inversion.
Compounds having growth hormone releasing activity
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, (2008/06/13)
Compounds that promote growth hormone releasing activity are disclosed. These compounds have the formula: A1-A2-X; A1-X′; or A1.-Y These compounds can be present in a pharmaceutical composition. The compounds can be used with a second compound that acts as an agonist at the growth hormone releasing hormone receptor or which inhibits the effects of somatostatin. These compounds can be used for a variety of uses such as treating hypothalamic pituitary dwarfism, osteoporosis, burns, or promoting wound healing.