Tandem Inter /Intra Cycloadditions. 3. The Stereochemical Influence of the Lewis Acid

Article abstract of DOI:10.1021/jo00024a005

trans-2-Phenylcyclohexanol has been employed as a chiral auxiliary in the inter <4 + 2>/intra <3 + 2> tandem cycloaddition of nitroalkanes with chiral vinyl ethers.A novel reversal of selectivity between cycloadditions catalyzed by the Lewis acids Ti(O-i-Pr)2Cl2 and MAPh has been discovered.