51849-22-0Relevant academic research and scientific papers
Consecutive C1-Homologation / Displacement Strategy for Converting Thiosulfonates into O,S-Oxothioacetals
Ielo, Laura,Pillari, Veronica,Miele, Margherita,Holzer, Wolfgang,Pace, Vittorio
, p. 5444 - 5449 (2020/10/12)
A conceptually intuitive synthesis of oxothioacetals is reported starting from thiosulfonates as electrophilic sulfur donors. The installation of a reactive CH2Cl motif with a homologating carbenoid reagent, followed by the immediate nucleophilic displacement with alcoholic groups [(hetero)-aromatic, aliphatic] offer a convenient access to the title compounds. Genuine chemoselectivity is uniformly observed in the case of multi-functionalized systems. (Figure presented.).
Expedient enantioselective synthesis of cermizine D
Veerasamy, Nagarathanam,Carlson, Erik C.,Carter, Rich G.
supporting information; experimental part, p. 1596 - 1599 (2012/06/05)
An efficient enantioselective synthesis of cermizine D has been developed that exploits the use of a common intermediate to access over 85% of the carbon backbone. Key steps include an organocatalyzed heteroatom Michael addition, a diastereoselective alky
A straightforward route to functionalized trans-diels-alder motifs
Lee, Jun Hee,Zhang, Yandong,Danishefsky, Samuel J.
supporting information; experimental part, p. 14330 - 14333 (2010/12/25)
A sequence consisting of a Lewis acid-catalyzed Diels-Alder reaction on a 2-halocyclohexenone, followed by reductive alkylation, provides a route to trans-fused octalinones bearing angular methyl groups with functionality corresponding to that which would have been possible from a trans-directed Diels-Alder reaction.
The enantioselective total synthesis of (-)-myltaylenol
Doye, Sven,Hotopp, Torsten,Wartchow, Rudolf,Winterfeldt, Ekkehard
, p. 1480 - 1488 (2007/10/03)
The unusual sesquiterpenoid alcohol (-)-myltaylenol (1) is synthesized by an intramolecular [4+2] cycloaddition of a chiral diene accessible from Hajos-Wiechert ketone by a sequence of reactions including stereoselective alkylation of an unsaturated ketone with thiophenylmethyl iodide as alkylation agent. As the link between diene and olefin a sulfonic ester group is used. The link permits control of the stereoselectivity of the [4+2] cycloaddition. After this key step the sulfonic ester group can be removed under oxidative conditions by molecular oxygen as oxidation agent, leading directly to a hydroxyketone that can be converted to (-)-myltaylenol by successive Shapiro reaction, regioselective hydroboration and Wittig reaction.
Palladium-catalyzed trimethylenemethane reaction to form methylenetetrahydrofurans. Reactions of substituted TMM precursors and mechanistic interpretation
Trost,King
, p. 408 - 422 (2007/10/02)
Alkyl-, phynyl-, vinyl-, and acetoxy-substituted palladium-trimethylenemethane (Pd-TMM) complexes react with aldehydes in the presence of organotin cocatalysts such as trimethylin acetate and trimethylin p-toluenesulfonate to give cycloadducts. The reactions of methyl-substituted TMM precursors 2a, 3, and 12 were studied most extensively. Two methylenetetrahydrofuran regioisomers, 10k and 10t, were produced in mixtures varying from 31:1 to 1:200 depending upon the TMM precursor, aldehyde, and cocatalyst. Conjugating substituents decrease the reactivity of the Pd-TMM complex, and only isomer 10t is available. The acetoxy substituent increases the reactivity of the organometallic and generated only 9k; however, the products cannot be isolated due to their lability. Electron-withdrawing substituents cause the complexes to be unreactive. Carveol-derived TMM precursors 23 and 2j give fused bicyclic products. Stereochemical analysis of these products showed that, contrary to olefin acceptors, aldehydes can, in some cases, attack the Pd complex on either face of the TMM moiety. These results indicate that trimethyltin chloride can be a very potent cocatalyst. The mechanism of the cycloaddition of aldehydes and, in particular, cocatalysis by organostannanes is discussed. The cocatalyst is believed to act by (1) aiding ring closure through the intermediacy of a stannyl ether and (2) acting as a Lewis acid to increase the rate of nucleophilic addition to the aldehyde.
Ketene. Part 26. The Reactions of 3,4-Dihydroisoquinoline N-Oxide with Ketenes, and an Attempted Synthesis of 3,4-Dihydro-3,3-dimethylquinoline N-Oxide
Evans, Andrew R.,Martin, Russell,Taylor, Giles A.,Yap, C. H. Maurice
, p. 1635 - 1640 (2007/10/02)
3,4-Dihydroisoquinoline N-Oxide reacts with dimethylketene to form a 1:2 adduct (8) in addition to compounds (6) and (7).With cyano-t-butylketene and ethoxycarbonyl-t-butylketene the adducts (9a) and (9b) are formed. 3,3-Dimethyl-1,2,3,4-tetrahydroquinoline (21a) has been synthesized, but attempts to convert this into the nitrone (20b) were unsuccessful.
Total Synthesis of (+)-Milbemycin β3
Baker, Raymond,O'Mahony, Mary J.,Swain, Christopher J.
, p. 1623 - 1634 (2007/10/02)
The total synthesis of (+)-milbemycin β3 has been achieved in two ways beginning from the appropriate spiroacetal moiety.In the first, coupling of a vinyl-lithium derivative (18) with the spiroacetal aldehyde (19), available from Swern oxidatio
Relative Reactivities of Various Sulfides, Selenides and Halides Towards SH2 Attack by Tributyltin Radicals
Beckwith, Athelstan L. J.,Pigou, Paul E.
, p. 77 - 87 (2007/10/02)
The order of reactivity towards SH2 attack by tributyltin radicals on various groups X in four different molecular environments (RCO2CH2X, RCH2OCH2X, XCH2CO2Et and RCH2X) has been found by competition experiments to be Br > PhSe > Cl > p-CNC6H4S > PhS > p-MeC6H4S > MeS.The mechanism of the reaction of chloromethyl phenyl sulfide with alkoxides is discussed.
PREPARATION AND REACTIONS OF trans- (R = Me, Ph or C6H4Me-p)
McPherson, Helen,Wardell, James L.
, p. 261 - 266 (2007/10/02)
Formation of trans- (R=Me, Ph or C6H4Me-p) has been achieved by the oxidative addition of ClCH2SR to (PPh3)4Pt in refluxing PhH.The reaction of ClCH2SMe with (PMe2Ph)4Pt led to cis-.The reaction of trans-(PPh3)2Pt(CH2S
