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.
Best Answer: a cbc test, as well as an ana test can take 24-48 hours to get definitive results. As most labs are not open on weekends, it could be as long as monday afternoon before they are completed and posted to your doctor. I could get all technical and tell you how these tests are done,but it would be a huge post.