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.
Whats the process and why does a blood hormone test take so long? It takes something like a week of working days-so that works out at 9 days due to weekends.eport Abuse. Depending on the hormone and/or the lab doing the test, it is usually measured by something called an RIA or radioimmune assay. The only reason it takes so long is because of the backlog of samples the lab has to run.