1 Due to the high degree of regio-and stereoselectivity (due to the concerted mechanism), the Diels-Alder reaction is a very powerful reaction and is widely used in synthetic organic chemistry.2  The reaction usually thermodynamically favourable due to the conversion of 2 &#960 -bonds into 2 new stronger &#963-bonds. Due to the high degree of regio-and stereoselectivity (due to the concerted mechanism), the Diels-Alder reaction is a very powerful reaction and is widely used in synthetic organic chemistry.
A standard echocardiogram or a fetal echocardiogram test usually takes about 30 to 60 minutes. A stress echocardiogram usually takes between 60 and 90 minutes.
The doctor will look at and listen to the electrical signals that travel from the needle to the EMG machine. The doctor then reads these signals. How long will these tests take? The tests usually take 40 to 90 minutes. You can do any of your normal activities, like eating, driving, and exercising, before the tests. You also can do your normal activities after the tests. There are no lasting side effects from the tests.