3907-02-6Relevant articles and documents
Total Synthesis of the Alleged Structure of Crenarchaeol Enables Structure Revision**
Cunha, Ana V.,Havenith, Remco W. A.,Holzheimer, Mira,Minnaard, Adriaan J.,Schouten, Stefan,Sinninghe Damsté, Jaap S.
supporting information, p. 17504 - 17513 (2021/07/06)
Crenarchaeol is a glycerol dialkyl glycerol tetraether lipid produced exclusively in Archaea of the phylum Thaumarchaeota. This membrane-spanning lipid is undoubtedly the structurally most sophisticated of all known archaeal lipids and an iconic molecule in organic geochemistry. The 66-membered macrocycle possesses a unique chemical structure featuring 22 mostly remote stereocenters, and a cyclohexane ring connected by a single bond to a cyclopentane ring. Herein we report the first total synthesis of the proposed structure of crenarchaeol. Comparison with natural crenarchaeol allowed us to propose a revised structure of crenarchaeol, wherein one of the 22 stereocenters is inverted.
Synthesis and Cytotoxicity Evaluation of C4- and C5-Modified Analogues of the α,β-Unsaturated Lactone of Pironetin
Huang, David S.,Wong, Henry L.,Georg, Gunda I.
supporting information, p. 520 - 528 (2017/04/10)
Pironetin is a natural product with potent antiproliferative activity that forms a covalent adduct with α-tubulin via conjugate addition into the natural product's α,β-unsaturated lactone. Although pironetin's α,β-unsaturated lactone is involved in its binding to tubulin, the structure–activity relationship at different positions of the lactone have not been thoroughly evaluated. For a systematic evaluation of the structure–activity relationships at the C4 and C5 positions of the α,β-unsaturated lactone of pironetin, twelve analogues of the natural product were prepared by total synthesis. Modifying the stereochemistry at the C4 and/or C5 positions of the α,β-unsaturated lactone of pironetin resulted in loss of antiproliferative activity in OVCAR5 ovarian cancer cells. While changing the C4 ethyl substituent with groups such as methyl, propyl, cyclopropyl, and isobutyl were tolerated, groups with larger steric properties such as an isopropyl and benzyl groups were not.
Chiral auxiliaries as docking/protecting groups in biohydroxylation: (S)-specific hydroxylation of enantiopure tert-butyl-substituted spirooxazolidines derived from cyclopentanone
Muenzer, Dieter F.,Griengl, Herfried,Moumtzi, Alexandra,Saf, Robert,Terzani, Tullio,De Raadt, Anna
, p. 793 - 796 (2007/10/03)
An enantiopure tert-butyl-substituted derivative of cyclopentanone, which is a vital member of the chiral docking/ protecting group series, is employed, for the first time, to stereoselectively (90% de) introduce an (S)-configured hydroxyl group onto an unactivated carbon atom present in the cyclopentane ring using the fungus Beauveria bassiana ATCC 7159. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.