Total synthesis of (+/-)-hedychenone: trimethyldecalin terpene systems via stepwise allenoate diene cycloaddition.
The total synthesis of hedychenone 1 is described. The cycloaddition of the hindered diene 2 and the allenecarboxylate 3 has been shown conclusively to proceed via the [2+2] cycloadduct 5 to give a 2:1 mixture of the desired formal Diels-Alder adducts, the exo and endo isomers 4xn and is thus a stepwise [4+2] cycloaddition. The exo isomer 4x was converted in four steps (reduction, oxidation, olefination, and desilylation) into hedychenone 1. [reaction: see text]
Jung
Michael E
ME
Department of Chemistry and Biochemistry, University of California-Los Angeles, 405 Hilgard Avenue, Los Angeles, CA 90095, USA. jung@chem.ucla.edu
Murakami
Masayuki
M
D000475:Alkenes / Q000737:chemistry; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis*; D007536:Isomerism; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D013729:Terpenes / Q000737:chemistry*; D030521:Zingiberaceae / Q000737:chemistry
D000475:Alkenes; D004224:Diterpenes; D013729:Terpenes; C517485:hedychenone