188945-41-7Relevant articles and documents
Synthetic Studies toward (?)-Cleistenolide: Highly Stereoselective Synthesis of New γ-Lactone Subunits
Sartori, Suélen K.,Miranda, Izabel L.,de Matos, Davi A.,Kohlhoff, Markus,Diaz, Marisa A.N.,Diaz-Mu?oz, Gaspar
, p. 757 - 766 (2021/03/17)
This study describes the stereoselective synthesis of two new γ-lactones in 6 and 3 steps and 19 and 32% yield, respectively, directed toward the total synthesis of the natural product (?)-cleistenolide. The starting material was an enantiomerically pure
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.
, 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.
{1,6}-transannular catalytic asymmetric Gosteli-Claisen rearrangement
Jaschinski, Tobias,Hiersemann, Martin
supporting information; experimental part, p. 4114 - 4117 (2012/10/08)
The first uncatalyzed and [Cu(R-box)L2](SbF6) 2-catalyzed {1,6}-transannular Gosteli-Claisen rearrangement of cyclic 2-alkoxycarbonyl-substituted allyl vinyl ethers to afford medium- and large-sized carbacycles is disclosed.
Total synthesis of the potent antitumor polyketide (-)-callystatin A
Dias, Luiz C.,Meira, Paulo R. R.
, p. 4762 - 4773 (2007/10/03)
A highly convergent and efficient total synthesis of the potent antitumor polyketide (-)-callystatin A is described. The synthesis required 19 steps from N-propionyl oxazolidinone 23 and produced the desired product in 3.5% overall yield.
Phosphonate modification for a highly (Z)-selective synthesis of unsaturated esters by Horner-Wadsworth-Emmons olefination
Touchard, Francois P.
, p. 1790 - 1794 (2007/10/03)
The Horner-Wadsworth-Emmons (HWE) reaction of various ethyl diarylphosphonoacetates with benzaldehyde, cyclohexane carboxaldehyde and octanal is reported. Selectivities of up to 98% at -78°C are obtained with the three substrates. Among all the phosphonates prepared, the reagent based on 2-tert-butylphenol proved to be especially efficient, with Z/E ratios close to 95:5 at 0°C. It appears thus to be the reagent of choice for the (Z)-selective HWE reaction with both aromatic and aliphatic aldehydes. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Highly Selective Synthesis of Z-Unsaturated Esters by Using New Horner-Emmons Reagents, Ethyl (Diarylphosphono)acetates
Ando, Kaori
, p. 1934 - 1939 (2007/10/03)
New Horner-Emmons reagents, ethyl (diarylphosphono)acetates 1, were prepared from triethyl phosphonoacetate, PCl5 the corresponding phenols. The reaction of 1 with several kinds of aldehydes in the presence of Triton B or NaH in THF solvent revealed that these reagents are useful for the synthesis of Z-unsaturated esters. Among the reagents examined, ethyl(di-o-tolylphosphono)-, [bis(o-ethylphenyl)phosphonol-, and [bis(o-isopropylphenyl)phosphono]acetates (1k-m) were found to be the most effective, giving Z-unsaturated esters with 93-99% selectivity.
