Asymmetric synthesis of alpha-substituted aldehydes by Pd-catalyzed asymmetric allylic alkylation-alkene isomerization-Claisen rearrangement.
[Structure: see text] Enantiospecific aliphatic Claisen rearrangement was realized with generally high chirality transfer. The requisite substrates were synthesized via Pd-catalyzed asymmetric allylic alkylation (AAA) from easily obtained starting materials. After protection, the resultant bisallyl ethers underwent olefin isomerization and in situ Claisen rearrangement (ICR) to generate alpha-chiral aldehydes. Remarkable chemoselectivity in the olefin isomerization step was observed. An asymmetric synthesis of communiol A was accomplished applying this methodology.
Trost
Barry M
BM
Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA. bmtrost@stanford.edu
Zhang
Ting
T
D000447:Aldehydes / Q000138:chemical synthesis* / Q000737:chemistry; D000478:Alkylation; D002384:Catalysis; D007536:Isomerism; D010165:Palladium / Q000737:chemistry*
D000447:Aldehydes; D010165:Palladium