34906-12-2Relevant academic research and scientific papers
Versatile Scope of a Masked Aldehyde Nitrone in 1,3-Dipolar Cycloadditions
Hoogenboom, Jorin,Zuilhof, Han,Wennekes, Tom
, p. 5550 - 5553 (2015)
A new masked aldehyde-containing nitrone 1 that is easily available through a facile one-step procedure has been developed. It undergoes a [3 + 2]-thermal cycloaddition with a wide range of dipolarophiles, affording isoxazolidine cycloadducts that are suitable for versatile postcycloaddition modifications. The acetal cycloadducts are acid-stable, but allow for acetal hydrolysis under mildly basic conditions. The isoxazolidine ring can be opened via an efficient one-pot procedure to give amine-protected γ-alcohols that can be further converted to furanose derivatives.
Reactions of 2-acyl-1,3-dithianes with α,β-unsaturated ketones: simple preparation of cyclohexendione monoacetals
Bulman Page,Harkin,Marchington
, p. 7235 - 7236 (1989)
2-Acyl-1,3-dithianes undergo efficient Lewis acid-catalysed addition to α,β-unsaturated ketones giving δ-diketones which suffer intramolecular aldol reaction to produce cyclohex-2-en-1,4 dione monoacetals and/or cyclohex-3-en-1,2-dione monoacetals.
Enantioselective organocatalytic aldehyde-aldehyde cross-aldol couplings. The broad utility of α-thioacetal aldehydes
Ian Storer,MacMillan, David W.C.
, p. 7705 - 7714 (2004)
An asymmetric proline catalyzed aldol reaction with α-thioacetal aldehydes has been developed. Thioacetal bearing aldehydes readily participate as electrophilic cross-aldol partners with a broad range of aldehyde and ketone donors. High levels of reaction
Chemoselectivity as a delineator of cuprate structure in Catalytic 1,4-Addition of Diorganozinc reagents to michael acceptors
Welker, Matthias,Woodward, Simon,Veiros, Luis F.,Calhorda, Maria Jose
experimental part, p. 5620 - 5629 (2010/07/16)
Reaction of the cyclic thioacetal (RS)2CHCHO [R = 1/2x-(CH 2)3] with HCCCOMe, followed by treatment with TsCl/DABCO (Ts = tosyl, DABCO= 1,4-diazabicyclo[2.2.2]octane) affords the mono-protected 1,4-benzoquinone dithioaceta
Anomalous C-C bond cleavage in sulfur-centered cation radicals containing a vicinal hydroxy group
Li, Zaiguo,Kutateladze, Andrei G.
, p. 8236 - 8239 (2007/10/03)
1,3-Dithianyl cation radicals having α-hydroxy-neopentyl or similar groups in position 2, which are generated via oxidative photoinduced electron transfer, undergo anomalous fragmentation necessitating refinement of the accepted mechanism. Experimental and computational data support a rationale in which proton abstraction from the hydroxy group in the initial cation radical does not cause a Grob-like fragmentation, but rather produces a neutral radical species, the alkoxy radical, that undergoes fragmentation in either direction, i.e., cleaving the C-C bond to dithiane or to the tertiary alkyl group.
Studies on the Mechanism of B(C6F5)3-Catalyzed Hydrosilation of Carbonyl Functions
Parks, Daniel J.,Blackwell, James M.,Piers, Warren E.
, p. 3090 - 3098 (2007/10/03)
The strong organoborane Lewis acid B(C6F5)3 catalyzes the hydrosilation (using R3SiH) of aromatic and aliphatic carbonyl functions at convenient rates with loadings of 1-4%. For aldehydes and ketones, the product silyl ethers are isolated in 75-96% yield; for esters, the aldehydes produced upon workup of the silyl acetal products can be obtained in 45-70% yield. Extensive mechanistic studies point to an unusual silane activation mechanism rather than one involving borane activation of the carbonyl function. Quantitative kinetic studies show that the least basic substrates are hydrosilated at the fastest rates; furthermore, increased concentrations of substrate have an inhibitory effect on the observed reaction rate. Paradoxically, the most basic substrates are reduced selectively, albeit at a slower rate, in competition experiments. The borane thus must dissociate from the carbonyl to activate the silane via hydride abstraction; the incipient silylium species then coordinates the most basic function, which is selectively reduced by [HB(C6F5)3]-. In addition to the kinetic data, this mechanistic proposal is supported by a kinetic isotope effect of 1.4(5) for the hydrosilation of acetophenone, the observation that B(C6F5)3 catalyzes H/D and H/H scrambling in silanes in the absence of substrate, computational investigations, the synthesis of models for proposed intermediates, and other isotope labeling and crossover experiments.
Lewis acid mediated addition of 2-acyl-1,3-dithianes to α,β-unsaturated ketones: Synthesis of cyclohexenedione mono-dithioacetals
Bulman Page, Philip C.,Marchington, Allan P.,Graham, Lisa J.,Harkin, Shaun A.,Wood, William W.
, p. 10369 - 10386 (2007/10/02)
2-Acyl-1,3-dithianes undergo Lewis acid-mediated conjugate addition to α,β-unsaturated ketones to provide 1,5-diketones which suffer base-catalyzed intramolecular aldol reaction to produce monodithioacetals of cyclohex-2-en-1,4-diones and cyclohex-3-en-1,
BIOCATALYTIC PREPARATION OF CHIRAL β-HYDROXY ESTERS SUBSTITUTED WITH HETERORING AT γ-POSITION
Kurumaya, Katsuyuki,Takatori, Kazuhiko,Isii, Rieko,Kajiwara, Masahiro
, p. 745 - 748 (2007/10/02)
Asymmetric reduction were examined of β-keto esters substituted with dithiane ring at γ-position with microorganism and gave the alcohol with high optical purity.Also the chiral carbinol with furan ring was obtained by the hydrolysis of the corresponding acetate with lipase or baker's yeast.
The 1,3-Dithian-2-ylmethoxycarbonyl (Dmoc) Group as Two-Step Amino Protective Function in Peptide Chemistry
Kunz, Horst,Barthels, Regina
, p. 833 - 845 (2007/10/02)
The 1,3-dithian-2-ylmethoxycarbonyl (Dmoc) group (4) as amino protective function is stable against bases and trifluoroacetic acid.The peptide condensation of Dmoc-amino acids is carried out applying the mixed anhydride or modified carbodiimide procedures
