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.
Redeeming your eBay Bucks. Earn $5.00 or more in eBay Bucks in a calendar quarter and we'll send you an eBay Bucks Certificate after the quarter ends. Your eBay Bucks Certificate is good for 30 days. To redeem your eBay Bucks Certificate: Sign in to eBay with the user ID you used to sign up for eBay Bucks.Start shopping. Make sure that the seller accepts PayPal. Pay for your item with PayPal before the expiration date on your eBay Bucks Certificate.In eBay checkout, your eBay Bucks Certificate appears next to the item subtotal. Select the checkbox to apply the eBay Bucks amount to your subtotal.ake sure that the seller accepts PayPal. Pay for your item with PayPal before the expiration date on your eBay Bucks Certificate. In eBay checkout, your eBay Bucks Certificate appears next to the item subtotal. Select the checkbox to apply the eBay Bucks amount to your subtotal.