Scope
An example of this procedure is the reaction of 2,2,6-trimethylcyclohexanone to the hydrazone by reaction with hydrazine and triethylamine in ethanol at reflux followed by reaction of the hydrazone with iodine in the presence of 2-tert-butyl-1,1,3,3-tetramethylguanidine (cheaper than DBU) in diethyl ether at room temperature. Another example can be found in the Danishefsky Taxol total synthesis.
In one study it is attempted to trap any reactive intermediate of this reaction with an internal alkene. When the hydrazone 1 in scheme 5 is reacted with iodine and triethylamine in toluene, the expected reaction product is not the di-iodide 10 through path B in a free radical mechanism. The actual process taking place is path A with elimination of HI to the diazo compound 4 followed by a diazoalkane 1,3-dipolar cycloaddition to the pyrazoline 5 in 85% yield.
Read more about this topic: Hydrazone Iodination
Famous quotes containing the word scope:
“As the creative adult needs to toy with ideas, the child, to form his ideas, needs toys—and plenty of leisure and scope to play with them as he likes, and not just the way adults think proper. This is why he must be given this freedom for his play to be successful and truly serve him well.”
—Bruno Bettelheim (20th century)
“For it is not the bare words but the scope of the writer that gives the true light, by which any writing is to be interpreted; and they that insist upon single texts, without considering the main design, can derive no thing from them clearly.”
—Thomas Hobbes (1579–1688)
“A country survives its legislation. That truth should not comfort the conservative nor depress the radical. For it means that public policy can enlarge its scope and increase its audacity, can try big experiments without trembling too much over the result. This nation could enter upon the most radical experiments and could afford to fail in them.”
—Walter Lippmann (1889–1974)