217300-17-9Relevant articles and documents
Total Synthesis of Leiodermatolide A via Transfer Hydrogenative Allylation, Crotylation, and Propargylation: Polyketide Construction beyond Discrete Allyl- or Allenylmetal Reagents
Krische, Michael J.,Roane, James,Siu, Yuk-Ming
supporting information, p. 10590 - 10595 (2021/07/28)
The total synthesis of leiodermatolide A was accomplished in 13 steps (LLS). Transfer hydrogenative variants of three carbonyl additions that traditionally rely on premetalated reagents (allylation, crotylation, and propargylation) are deployed together i
A (isopropoxy silicon) method for preparing chloromethane
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Paragraph 0016; 0017; 0018; 0019; 0020; 0021; 0022; 0023, (2017/08/25)
The invention discloses a method for preparing (isopropoxy silicon) chloromethane, relates to the technical field of chemical synthesis, and particularly relates to synthesis of a protective agent in the field of oligonucleotides. The method comprises the following steps: feeding paraformaldehyde to triisopropyl silanol with temperature of -10 DEG C to 0 DEG C, introducing hydrogen chloride gas, and reacting until reaction is ended; adding n-hexane to a reaction system, standing and separating out a water phase; and taking an organic phase, and carrying out reduced pressure rectification, so as to obtain the (isopropoxy silicon) chloromethane. The (isopropoxy silicon) chloromethane has the advantages of high yield, high purity, simple process and low cost, and is simple to operate in the production process and suitable for industrial production.
Synthesis of the C(1)-C(13) Fragment of Leiodermatolide via Hydrogen-Mediated C-C Bond Formation
Roane, James,Wippich, Julian,Ramgren, Stephen D.,Krische, Michael J.
supporting information, p. 6634 - 6637 (2017/12/26)
The C(1)-C(13) fragment of the antimitotic marine macrolide leiodermatolide is prepared in seven steps via hydrogenative and transfer-hydrogenative reductive C-C couplings. A hydrogen-mediated reductive coupling of acetylene with a Roche-type aldehyde is used to construct C(7)-C(13). A 2-propanol-mediated reductive coupling of allyl acetate with (E)-2-methylbut-2-enal at a low loading of iridium (1 mol %) is used to construct C(1)-C(6), which is converted to an allylsilane using Oestereich's copper-catalyzed allylic substitution of Si-Zn reagents. The union of the C(1)-C(6) and C(7)-C(13) fragments is achieved via stereoselective Sakurai allylation.
Reliable chemical synthesis of oligoribonucleotides (RNA) with 2′-O-[(triisopropylsilyl)oxy]methyl(2′-O-tom)-protected phosphoramidites
Pitsch, Stefan,Weiss, Patrick A.,Jenny, Luzi,Stutz, Alfred,Wu, Xiaolin
, p. 3773 - 3795 (2007/10/03)
A method for the introduction of the 2′-O-[(triisopropylsilyl)oxy]methyl (=tom) group into N-acetylated, 5′-O-dimethoxytritylated ribonucleosides is presented. The corresponding 2′-O-tom-protected phosphoramidite building blocks were obtained in pure form and were successfully employed for the routine synthesis of oligoribonucleotides on DNA synthesizers. Under DNA coupling conditions (2.5 min coupling time for a 1.5-μmol synthesis scale) and with 5-(benzylthio)-1H-tetrazole (BTT) as activator, 2′-O-tom-protected phosphoramidites exhibited average coupling yields >99.4%. The combination of N-acetyl and 2′-O-tom protecting groups allowed a reliable and complete two-step deprotection, first with MeNH2 in EtOH/H2O and then with Bu4NF in THF, without concomitant destruction of the product RNA sequences.
Fast and reliable automated synthesis of RNA and partially 2'-O- protected precursors ('caged RNA') based on two navel, orthogonal 2'-O- protecting groups. Preliminary communication
Pitsch, Stefan,Weiss, Patrick A.,Wu, Xiaolin,Ackermann, Damian,Honegger, Thomas
, p. 1753 - 1761 (2007/10/03)
Two sets of RNA phosphoramidites, carrying the (fluoride-labile) 2'-O- [(triisopropylsilyl)oxy]methyl (=tom) group and the (photolabile) [(R)-1-(2- nitrophenyl)ethoxy]methyl (= (R)-npeom) group, were prepared (see 1-4 and 5- 8, resp.). The two protecting groups were completely orthogonal to each other. Three ribozyme-substrate constructs, protected each by a (R)-npeom group, were synthesized; on photolysis, efficient cleavage of this remaining protecting group occurred (Scheme 3). It could be demonstrated that the presence of one (R)-npeom group within a RNA strand has only a minor influence on the pairing properties of corresponding duplexes.
Ribonucleoside-derivative and method for preparing the same
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, (2008/06/13)
The ribonucleoside-derivatives serve for the synthesis of ribonucleic acids and comprise a triple substituted silyloxymethyl-group as a protection-group on the oxygen atom in 2'-position. The ribonucleoside-derivatives may be suitably protected on the nucleo-base and on the oxygen in 5'-position also. The new protection-groups in 2'-O-position are superior to conventional such protection-groups as they are not subject to isomerization and give higher coupling yields. The general formula of the ribonucleoside-derivative is: STR1 whereby R1 is a base of the purine- or pyrimidine-family or a derivative of such a base, R2 is a proton or a substituted derivative of phosphonic acid, R3 is a proton or a suitable protection-group, R4, R5, R6 are advantageously three identical or different alkyl- or aryl-substituents which together comprise between 6 and 30 carbon atoms.