96516-91-5Relevant academic research and scientific papers
Selective alkyl ether cleavage by cationic bis(phosphine)iridium complexes
Jones, Caleb A. H.,Schley, Nathan D.
supporting information, p. 1744 - 1748 (2019/02/20)
Catalysts capable of heterolytic silane activation have been successfully applied to the conversion of alkyl ethers to silyl ethers via C-O bond cleavage. The previously-reported cationic pincer-supported iridium complex for this transformation suffers fr
Reactions of Carbenes with Oxetane and with Oxetane/ Methanol Mixtures
Kirmse, Wolfgang,Lelgemann, Rudolf,Friedrich, Klaus
, p. 1853 - 1863 (2007/10/02)
Ethoxycarbonylcarbene, bis(methoxycarbonyl)carbene, phenylcarbene (17a), diphenylcarbene (17b), fluorenylidene (17c), 2-furylcarbene (31a), 2-furyl(phenyl)carbene (31b), 4-oxo-2,5-cyclohexadienylidene (40), and 4,4-dimethyl-2,5-cyclohexadienylidene (53) were generated by photolysis of the appropriate diazo compounds.With neat oxetane, most of these carbenes react by competitive C-H insertion (B -> A, Scheme 1) and ylide formation (B -> C). 31a and 40 do not insert into C-H bonds; 31b does not attack oxetane but rearranges exclusively with formation of 26.The ylides undergo Stevens rearrangement to give tetrahydrofurans (C -> D) and α',β-elimination, leading to allyl ethers (C -> E).With oxetane/ methanol mixtures, the intervention of oxonium ions (H) is indicated by the formation of 1,3-dialkoxypropanes (I).The oxonium ions arise either by protonation of the ylides (C -> H) or by protonation of the carbenes (B -> G), followed by electrophilic attack of the carbocations (G) at oxetane (G -> H).The former route is followed by the alkoxycarbonylcarbenes and by 40; the ylides derived from the remaining carbenes do not react with methanol, owing to their rapid Stevens rearrangements.Protonation of the carbenes 17b, 31, and 53 is clearly indicated by their product ratios and, for 31, by the formation of isomeric ethers (33, 36).The more electrophilic carbenes discriminate but slightly between oxetane and methanol while the more nucleophilic carbenes (17b, 31, 53) prefer the protic methanol strongly over the aprotic oxetane. Key Words: Carbenes/ Oxygen ylides/ Stevens rearrangement/ Oxonium ions/ Insertion, O-H/ Ylides
Synthesis and Utilization of the Chiral Synthon Methyl 3-O-Benzyl-2,4,6-trideoxy-6-iodo-α-D-erythro-hexopyranoside in the Synthesis of a Potent HMG-CoA Reductase Inhibitor
Prugh, John D.,Rooney, C. Stanley,Deana, Albert A.,Ramjit, Harri G.
, p. 648 - 657 (2007/10/02)
Synthesis of the potent HMG-CoA reductase inhibitor 1a has been achieved by utilizing the chiral synthon 2, which was prepared from methyl α-D-glucopyranoside in 12 steps (6 new).A key step in this sequence, which should have general applicability for the
OXYGEN YLIDES-I. REACTIONS OF CARBENES WITH OXETANE
Friedrich, Klaus,Jansen, Ulrich,Kirmse, Wolfgang
, p. 193 - 196 (2007/10/02)
The ylides generated from carbenes (:CH2, :CHCO2Et, :CHPh) and oxetane in the presence of methanol undergo Stevens rearrangement and protonation competitively, yielding tetrahydrofurans and 1,3-dialkoxycyclopropanes as major products.
