6533b859fe1ef96bd12b80ca

RESEARCH PRODUCT

Diastereoselective synthesis of antiquorin and related polyoxygenated atisene-type diterpenes

Carmen Ramírez De ArellanoIgnacio De Alfonso MarzalIsmael NavarroAna C. CuñatAntonio GrisAntonio AbadConsuelo Agulló

subject

Allylic rearrangementCyclopropanationStereochemistryOrganic ChemistryRegioselectivityBiochemistryCyclopropanechemistry.chemical_compoundchemistryIntramolecular forceDrug DiscoveryEpimerDiterpeneDiels–Alder reaction

description

Abstract A diastereoselective approach to polyoxygenated atisene-type diterpenes starting from (S)-(+)-carvone is described. The key steps used in the preparation of the atisene framework are an intramolecular Diels–Alder reaction, an intramolecular diazoketone cyclopropanation, an endocyclic cyclopropane ring cleavage and the regioselective reduction of an allylic bromide by a low-valent chromium species. The synthesis of natural atisanes antiquorin (1), atis-16-ene-3,14-dione (3), atis-16-ene-2,3,14-trione (8) and 3β-hydroxy-atis-16-ene-2,14-dione (9) following this approach is presented. Also described is the synthesis of 18-hydroxy-atis-16-ene-3,14-dione (5), the structure erroneously assigned to an atisene isolated from the Fijian plant Euphorbia fidjiana. This work shows that the natural atisene isolated from this plant is, in fact, the epimer at C-4 of this compound.

yearjournalcountryeditionlanguage
2007-02-01Tetrahedron
https://doi.org/10.1016/j.tet.2006.11.083