Probing the Lewis acid-catalyzed intramolecular Diels-Alder cyclizations of allylic alkoxy-substituted (Z)-1,3-dienes.
[reaction: see text] The Lewis acid-promoted Diels-Alder reaction of (E,Z,E)-trienal 1 provides not only the expected cis-fused cycloadduct 16 but also the trans-fused products 17 and 18. Trans-fused cycloadducts 17 and 18 are also products of the Lewis acid-promoted cyclization of (E,Z,E)-trienyl acetal 2. These products presumably derive from a stepwise cyclization pathway.
Dineen
Thomas A
TA
Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.
Roush
William R
WR
D000143:Acids / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013237:Stereoisomerism
D000143:Acids; D004224:Diterpenes