136786-35-1Relevant academic research and scientific papers
Synthesis of stereopure acyclic 1,5-dimethylalkane chirons: Building blocks of highly methyl-branched natural products
Li, Nan-Sheng,Piccirilli, Joseph A.
, p. 9633 - 9641 (2013/10/22)
An efficient synthetic method towards stereopure acyclic 1,5-dimethylalkane building blocks from methyl (2R)-3-hydroxy-2-methylpropionate (R)-1 (>99% ee) and methyl (2S)-3-hydroxy-2-methylpropionate (S)-1 (>99% ee) through a series of chemical transformat
Highly stereocontrolled total synthesis of β-d-mannosyl phosphomycoketide: A natural product from mycobacterium tuberculosis
Li, Nan-Sheng,Scharf, Louise,Adams, Erin J.,Piccirilli, Joseph A.
, p. 5970 - 5986 (2013/07/26)
β-d-Mannosyl phosphomycoketide (C32-MPM), a naturally occurring glycolipid found in the cell walls of Mycobacterium tuberculosis, acts as a potent antigen to activate T-cells upon presentation by CD1c protein. The lipid portion of C32-MPM contains a C32-mycoketide, consisting of a saturated oligoisoprenoid chain with five chiral methyl branches. Here we develop several stereocontrolled approaches to assemble the oligoisoprenoid chain with high stereopurity (>96%) using Julia-Kocienski olefinations followed by diimide reduction. By careful choice of olefination sites, we could derive all chirality from a single commercial compound, methyl (2S)-3-hydroxy-2-methylpropionate (>99% ee). Our approach is the first highly stereocontrolled method to prepare C32-MPM molecule with >96% stereopurity from a single >99% ee starting material. We anticipate that our methods will facilitate the highly stereocontrolled synthesis of a variety of other natural products containing chiral oligoisoprenoid-like chains, including vitamins, phytol, insect pheromones, and archaeal lipids.
Tumescenamide C, an antimicrobial cyclic lipodepsipeptide from Streptomyces sp.
Kishimoto, Shinji,Tsunematsu, Yuta,Nishimura, Shinichi,Hayashi, Yutaka,Hattori, Akira,Kakeya, Hideaki
, p. 5572 - 5578 (2012/09/08)
Tumescenamide C, a new cyclic lipodepsipeptide, was isolated from a culture broth of an actinomycete Streptomyces sp. KUSC-F05. Tumescenamide C was a congener of tumescenamides A and B, representing a sixteen-membered ring system, consisting of two proteinogenic and three non-proteinogenic amino acids, to which a methyl-branched fatty acid was attached. The planar structure was determined by spectroscopic analysis, while its absolute stereochemistry was determined by chemical degradation and asymmetric synthesis. Tumescenamide C exhibited antimicrobial activity with high selectivity against Streptomyces species.
Total synthesis and biological evaluation of (+)-neopeltolide and its analogues
Fuwa, Haruhiko,Saito, Asami,Naito, Shinya,Konoki, Keiichi,Yotsu-Yamashita, Mari,Sasaki, Makoto
supporting information; experimental part, p. 12807 - 12818 (2010/06/17)
The stereocontrolled total synthesis of the originally proposed (1) and correct (2) structures of (+)-neopeltolide, a novel marine macrolide natural product with highly potent antiproliferative activity against several cancer cell lines as well as potent antifungal activity, has been achieved by exploiting a newly developed SuzukiMiyaura coupling/ring-closing metathesis strategy. Alkylborate 44, which was generated in situ from iodide 34, was coupled with enol phosphate 8 by a Suzuki-Miyaura coupling. Ring-closing metathesis of the derived diene 45 followed by stereoselective hydrogenation afforded tetrahydropyran 47 as a single stereoisomer in high overall yield from 34. Our convergent strategy enabled us to construct the 14-membered macrolactone core structure of 2 in a rapid and efficient manner. Total synthesis and biological evaluation of synthetic intermediates and designed synthetic analogues, performed to establish the structure-activity relationships of 2, led to the discovery of a structurally simple yet potent cytotoxic analogue, 9-demethylneopeltolide (54).
Total Syntheses of Epothilones B and D
Mulzer, Johann,Mantoulidis, Andreas,Oehler, Elisabeth
, p. 7456 - 7467 (2007/10/03)
Total syntheses of the microtubule stabilizing antitumor drugs epothilone B and D are described, starting from optically pure (S)-malic acid and methyl (R)-3-hydroxy-2-methylpropionate. The synthesis is highly convergent by coupling the three fragments C1-C6 (fragment D), C7-C10 (fragment C), and C11-C21 (fragment B). Key steps are two stereoselective Wittig type olefinations to generate the 12,13- and 16,17-double bonds, an enantioselective Mukaiyama aldol addition to synthesize fragment D, and a sulfone anion allyl iodide alkylation to connect fragments B and C. Finally fragment D was attached to the B + C fragment via aldol addition.
Synthetic studies on halichondrin B, an antitumor polyether macrolide isolated from a marine sponge. 9. Synthesis of the C16 - C36 unit via stereoselective construction of the D and E rings
Horita, Kiyoshi,Nagasawa, Masaaki,Sakurai, Youji,Yonemitsu, Osamu
, p. 1199 - 1216 (2007/10/03)
The C16 - C36 unit of halichondrin B was stereoselectively synthesized via the aldol condensation of two C16 - C26 esters with the previously synthesized C27 - C36 aldehyde followed by E ring construction. The C16 - C26 esters were prepared starting from (2S)-3-hydroxy-2-methylpropionic acid and L-tartaric acid via construction of the D ring by iodoetherification.
Sodium Sulphide as a Mild and Selective Desilylating Reagent
Schmittberger, T.,Uguen, D.
, p. 7445 - 7448 (2007/10/02)
diphenyl-t-butoxyslyl (i.e.DPTBOS) derivatives of alcohols are selectively cleaved by nonahydrated sodium sulphide in ethanol, the order of reactivity being: primary ca. secondary>>tertiary.The corresponding t-butyldimethylsilyl and diphenyl-t-butylsilyl derivatives remain unaffected in these conditions.
Total Synthesis of (-)-Stemoamide
Williams, David R.,Reddy, Jayachandra P.,Amato, George S.
, p. 6417 - 6420 (2007/10/02)
An enantiocontrolled total synthesis of the tricyclic alkaloid, stemoamide (2), is reported. Key Words: Asymmetric aldol; chiral butyrolactone synthesis; selective 1,3-acyclic diol formation.
Studies directed toward the total synthesis of tetronolide 1. An enantioselective synthesis of the octahydronaphthalene unit
Boeckman Jr., Robert K.,Barta, Thomas E.,Nelson, Scott G.
, p. 4091 - 4094 (2007/10/02)
An efficient enantioselective route to the octahydronaphthalene unit present in tetronolide (1), the stereochemically complex aglycone common to the tetrocarcins, a novel group of antitumor substances, is described. The sequence employs the intramolecular
