1 The Diels-Alder reaction is a conjugate addition reaction of a conjugated diene to an alkene (the dienophile) to produce a cyclohexene. 2  The simplest example is the reaction of 1,3-butadiene with ethene to form cyclohexene:3  The analogous reaction of 1,3-butadiene with ethyne to form 1,4-cyclohexadiene is also known: 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.
Best Answer: Buyers have up 7 days to pay for an item before you as a seller can open an unpaid item case with ebay. They have a whole process they ask that sellers follow: Buyers automatically enter into a legally binding contract to purchase the item from the seller if they win an online auction or use the Buy It Now feature.
how long does it take for payment to clear? Hi i'm new to all of this i have just recently sold an item on ebay for the first time and the payment is in my paypal but it says pending and because i'm a new seller on ebay it can take 21 days what i want to know is does it really take 21 days? Re: how long does it take for payment to clear? on â07-11-2011 05:02 PM. Hi i'm new to all of this i have just recently sold an item on ebay for the first time and the payment is in my paypal but it says pending and because i'm a new seller on ebay it can take 21 days what i want to know is does it really take 21 days? clear.