The Asymmetric Diels-Alder Cycloaddition Using Ethyl(-)-(Z)-(R)s-2-methyl-3-(p-tlylsulfinyl)propenoate: Application to an Enantioselective Synthesis of (+)-epi-β-Santalene

Article abstract of DOI:10.1246/bcsj.61.467

The Diels-Alder reaction of ethyl (-)-(Z)-(R)_s-2-methyl-3-(p-tolylsulfinyl)propenoate (6) with cyclopentadiene gave the adducts, 7, 8, and 9 in a high diastereoselective manner.The cycloadduct 7 was transformed into the acetal (-)-25.The racemic 25 was used as an intermediate in the synthesis of (+/-)-β-santalol.Thus, the chiral acetal (-)-25 should provide a route to (-)-Β-santalol.The cycloadduct 8 was converted into (+)-epi-β-santalene in 11 steps.