24163-93-7Relevant articles and documents
Mild TiIII- and Mn/ZrIV-catalytic reductive coupling of allylic halides: Efficient synthesis of symmetric terpenes
Barrero, Alejandro F.,Herrador, M. Mar,Quilez Del Moral, Jose F.,Arteaga, Pilar,Arteaga, Jesus F.,Dieguez, Horacio R.,Sanchez, Elena M.
, p. 2988 - 2995 (2007)
(Chemical Equation Presented) Two new efficient methods for the regioselective homocoupling of allylic halides using either catalytic Ti III or the combination Mn/ZrIV catalyst have been developed. The regio- and stereoselectivity of the process proved to increase significantly when the Mn/ZrIV catalyst is used as the coupling reagent and when cyclic substituted allylic halides are used as substrates. The use of Lewis acids such as collidine hydrochloride allowed the quantity of catalyst to be lowered up to 0.05 equiv. We have proved the utility of these protocols with the synthesis of different terpenoids such as (+)-β-onoceradiene (1), (+)-β-onocerine (2), squalene (5), and advanced key-intermediates in the syntheses of (+)-cymbodiacetal (3) and dimeric ent-kauranoids as xindongnin M (4a).
Enzymatic formation of pyrrole-containing novel cyclic polyprenoids by bacterial squalene:hopene cyclase
Tanaka, Hideya,Noma, Hisashi,Noguchi, Hiroshi,Abe, Ikuro
, p. 3085 - 3089 (2006)
A convergent synthesis provided two pyrrole-containing squalene analogues, in which a C20 isoprene unit is connected to pyrrole, 2-(geranylgeranyl)pyrrole and 2-(farnesyldimethylallyl)pyrrole. When incubated with recombinant squalene:hopene cyclase from Alicyclobacillus acidocaldarius, 2-(farnesyldimethylallyl)pyrrole was enzymatically converted to a 10:1 mixture of a tricyclic and a bicyclic unnatural novel polyprenoids, whereas 2-(geranylgeranyl)pyrrole was not a substrate for the enzyme.
Moenomycin analogues with modified lipid side chains from indium-mediated Barbier-type reactions
Vogel, Stefan,Stembera, Katherina,Hennig, Lothar,Findeisen, Matthias,Giesa, Sabine,Welzel, Peter,Lampilas, Maxime
, p. 4139 - 4146 (2001)
From moenomycin A both the chromophore part and the lipid side chain were degraded by ozonolysis to give an analogue with a glycolaldehyde unit in 2-position of the glyceric acid moiety. The aldehyde was converted to a number of homoallylic alcohols by indium-mediated Barbier-type reactions with allylic and benzylic halides. With exception of the phytyl bromide-derived reaction product all compounds were antibiotically inactive.
Total synthesis and morphogenesis-inducing activity of (±)-thallusin and its analogues
Nishizawa, Mugio,Iyenaga, Tomoaki,Kurisaki, Takahiro,Yamamoto, Hirofumi,Sharfuddin, Mohammed,Namba, Kosuke,Imagawa, Hiroshi,Shizuri, Yoshikazu,Matsuo, Yoshihide
, p. 4229 - 4233 (2007)
Total synthesis of (±)-thallusin was achieved using Hg(OTf)2·PhNMe2-induced olefin cyclization, and Suzuki coupling with a pyridylboronic acid derivative. Hg(OTf)2 also acted as a catalyst to isomerize the double bond into
Synthetic endeavors toward 2-nitro-4-alkylpyrroles in the context of the total synthesis of heronapyrrole C and preparation of a carboxylate natural product analogue
Schmidt, Jens,Stark, Christian B. W.
, p. 1920 - 1928 (2014)
The synthesis of 2-nitro-4-oligoprenyl-substituted pyrrole derivatives relevant to the heronapyrroles and related natural products was investigated. Among numerous approaches, nitration of a 3-farnesyl-substituted unprotected pyrrole using AcONO2 gave the best results, albeit still with unsatisfactory yield and regioselectivity. Therefore, the synthesis of (-)-heronapyrrole C acid, an analogue of the naturally occurring antibiotic heronapyrrole C carrying a bioisosteric carboxylate in place of the nitro group, was examined. In lieu of the unsatisfactory nitration, a regioselective acylation with Cl3CCOCl was carried out (>8:1 regioselectivity, in contrast to the 1:1.3 ratio for the nitration). The trichloromethyl ketone was converted to the desired acid in a haloform reaction at the final stage of the synthesis. Further key steps of the analogue synthesis involved a position- and stereoselective Corey-Noe-Lin dihydroxylation and an organocatalytic double Shi epoxidation. A biomimetic polyepoxide cyclization cascade established the bis-THF backbone. Thus, (-)-heronapyrrole C acid was synthesized in eight steps (14.5% overall yield) from commercially available starting materials.
THE SYNTHESIS OF ISOPRENOID (PHOSPHINYLMETHYL)PHOSPHONATES
Biller, Scott A.,Forster, Cornelia
, p. 6645 - 6658 (1990)
A synthetic route to isoprenoid (phosphinylmethyl)phosphonates (PMPs), stable analogues of the biologically important diphosphates, is described.This method involves the reaction of an α-phosphonate carbanion with an isoprenoid phosphonochloridate to provide the PMP triesters, followed by ester cleavage with TMSBr or TMSI. 13C NMR, 31P NMR, 19F NMR and FAB-MS data were employed for the characterization of PMP salts and triesters.
Mechanistic Investigations of Two Bacterial Diterpene Cyclases: Spiroviolene Synthase and Tsukubadiene Synthase
Rabe, Patrick,Rinkel, Jan,Dolja, Etilia,Schmitz, Thomas,Nubbemeyer, Britta,Luu, T. Hoang,Dickschat, Jeroen S.
, p. 2776 - 2779 (2017)
The mechanisms of two diterpene cyclases from streptomycetes—one with an unknown product that was identified as the spirocyclic hydrocarbon spiroviolene and one with the known product tsukubadiene—were investigated in detail by isotope labeling experiment
Formation and Alkylation of Anions of Bis(methylsulfonyl)methane
Castro, Alfredo,Spencer, Thomas A.
, p. 3496 - 3499 (1992)
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A stereoselective hydroamination transform to access polysubstituted indolizidines
Pronin, Sergey V.,Tabor, M. Greg,Jansen, Daniel J.,Shenvi, Ryan A.
, p. 2012 - 2015 (2012)
Stereoselective, intramolecular, formal hydroamination of dienamines via directed hydroboration is reported. Four stereocenters are set in the process. Natural and unnatural indolizidine alkaloids can be synthesized from simple unsaturated amines using the title process.
Regiospecific Synthesis of Calcium-Independent Daptomycin Antibiotics using a Chemoenzymatic Method
Mupparapu, Nagaraju,Lin, Yu-Hsin Cindy,Kim, Tae Ho,Elshahawi, Sherif I.
supporting information, p. 4176 - 4182 (2021/02/01)
Daptomycin (DAP) is a calcium (Ca2+)-dependent FDA-approved antibiotic drug for the treatment of Gram-positive infections. It possesses a complex pharmacophore hampering derivatization and/or synthesis of analogues. To mimic the Ca2+-binding effect, we used a chemoenzymatic approach to modify the tryptophan (Trp) residue of DAP and synthesize kinetically characterized and structurally elucidated regiospecific Trp-modified DAP analogues. We demonstrated that the modified DAPs are several times more active than the parent molecule against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria. Strikingly, and in contrast to the parent molecule, the DAP derivatives do not rely on calcium or any additional elements for activity.
BIOSYNTHESIS OF CHEMICALLY DIVERSIFIED NON-NATURAL TERPENE PRODUCTS
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Page/Page column 116-120; 130-133; 138-139; 146-147, (2021/05/15)
The disclosure relates to compounds of the formulae (l)-(IV) and their use as substrates for making terpenoids. New substrates for terpene biosynthesis and methods for making new types of terpenes are described herein. Diterpenes occupy a unique molecular
