Studies on an Oxidative 1,4-Addition to s-trans-1,3-Dienes, a Key Reaction in a Strigol Total Synthesis

• Published in: European journal of organic chemistry Vol. 2003; no. 23; pp. 4640 - 4653
• Main Authors: Galkina, Anna, Buff (née Kranz), Angelika, Schulz (née Samson), Emmanuelle, Hennig, Lothar, Findeisen, Matthias, Reinhard, Gerd, Oehme, Ramona, Welzel, Peter
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2003; WILEY‐VCH Verlag; Wiley
• Subjects: Chemistry; Chemistry, Organic; Olefination; Oxidation; Palladium; Physical Sciences; Science & Technology; Stereochemistry; STEREOISOMERS; PALLADIUM-CATALYZED SUBSTITUTION; HORNER-WITTIG REACTION; oxidation; FORMAL TOTAL-SYNTHESIS; REARRANGEMENT; ALLYLIC ALCOHOLS; stereochemistry; palladium; SYSTEMS; GERMINATION STIMULANT; (+)-STRIGOL; PHOSPHINE OXIDES; olefination
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.200200671

Oxidation of 4,6‐heptadienoic acid systems with hydrogen peroxide in the presence of a catalytic amount of diphenyl diselenide leads to 5‐(3‐hydroxypropenyl)dihydrofuran‐2‐one systems with defined relative configuration at the 4 and 7 positions (carboxylic acid numbering). A system having a six‐membered ring as part of the s‐trans‐diene system was an intermediate in a strigol total synthesis; a second system lacking the six‐membered ring is the subject of the present publication. We accomplished a stereoselective synthesis of the diene system by (i) trapping a π‐allyl palladium complex with lithium diphenylphosphinite to give an allylic diphenylphosphane oxide and (ii) a subsequent Horner−Wittig reaction. The species that brings about the oxidative 1,4‐addition is benzeneperoxyseleninic acid. We also report observations that shed some light on the mechanism. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)