Remarkable Diastereoselectivity Eserted by Dienophile Configuration in Intramolecular Diels-Alder Reaction of Electron Deficient Heterodienes: New Chiral Entry into the Secoiridoid Monoterpenes and the Heteroyohibine Indole Alkaloids
Studies in Lewis acid and LiClO4 (or Nafion-H) catalysed ionic Diels-Alder reactions of chiral and achiral olefinic acetals respectively
作者:R Kumareswaran、Padma S Vankar、M Venkat Ram Reddy、Sangeeta V Pitre、Raja Roy、Yashwant D Vankar
DOI:10.1016/s0040-4020(98)01088-6
日期:1999.1
Chiral olefinic acetals derived from crotonaldehyde undergo ionicDiels-Alderreaction giving the corresponding cycloadducts in moderate to good diastereoselectivities. A variety of achiral olefinic acetals react with isoprene and cyclopentadiene to form the cycloadducts in good to excellent yields when catalysed by 4M LiClO4 in nitromethane or by Nafion-H in dichloromethane.