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.
We contact the buyer to request payment. Timeline: We contact the buyer immediately after you open the case. The buyer has 4 days from the time you opened the case to pay. If the buyer doesn't pay within 4 days, you can close the case and an unpaid item may be recorded on the buyer's account.If the buyer has contacted you and you've agreed to extend the payment deadline, you can wait up to 36 days after the listing ended to close the case.e contact the buyer to request payment. Timeline: We contact the buyer immediately after you open the case. The buyer has 4 days from the time you opened the case to pay. If the buyer doesn't pay within 4 days, you can close the case and an unpaid item may be recorded on the buyer's account.