1072-72-6Relevant articles and documents
Synthesis and characterization of sulfide, sulfoxide and sulfone derivatives of thiopyran: antimicrobial evaluation
Pasha, Ghasem Firouzzade,Asghari, Sakineh,Tajbakhsh, Mahmoud,Mohseni, Mojtaba
, p. 7291 - 7306 (2017)
Abstract: A series of thiopyran derivatives and their oxidized analogous forms were synthesized and characterized by FT-IR, 1H, 13C, 31P NMR and mass spectroscopy techniques. The antibacterial and antifungal activities of these synthesized materials were evaluated against Staphylococcus aureus and Bacillus subtilis, as Gram-positive bacteria, and Escherichia coli and Pseudomonas aeruginosa, as Gram-negative bacteria, as well as the fungus Candida albicans. The results revealed that thiopyran S,S-dioxides are the most effective against all the bacteria studied in this work. Furthermore, thiopyran S-oxides showed excellent antifungal activity against Candida albicans.
HCl-catalyzed stereoselective Mannich reaction in H2O-SDS system
Akiyama, Takahiko,Matsuda, Keiichiro,Fuchibe, Kohei
, p. 322 - 324 (2005)
HCl-catalyzed Mannich reaction of cyclic ketone, aromatic aldehyde, and aromatic amine proceeded smoothly in water in the presence of SDS to afford the corresponding β-amino ketone with high anti selectivity.
Influence of the β-alkoxy group on the diastereoselectivity of aldol reactions of tetrahydro-4H-thiopyran-4-one with 4-alkoxytetrahydro-2H-thiopyran-3-carboxaldehydes
Ward, Dale E.,Sales, Marcelo,Man, Chuk C.,Shen, Jianheng,Sasmal, Pradip K.,Guo, Cheng
, p. 1618 - 1629 (2002)
The diastereoselectivity of the aldol reaction of tetrahydro-4H-thiopyran-4-one (3) with 1,4-dioxa-8-thiaspiro[4.5]decane-6-carboxaldehyde (9a) under a variety of conditions is examined. Under optimized conditions, three of the four possible diastereomers from this aldol reaction can be obtained selectively (3-16:1). Reactions of 9a with the Li, B, Mg(II), and Ti(IV) enolates of 3 and with the corresponding trimethylsilyl enol ether 4b in the presence of BF3·OEt2, SnCl4, or TiCl4 as promoters gave the Felkin adducts exclusively (>95%) as mixtures of syn (11a) and anti (12a) diastereomers. Use of the "amine-free" Li enolate of 3 gave 12a with a much higher diastereoselectivity (9:1) and yield (70%) than that obtained using the lithium diisopropylamide-generated Li enolate of 3 (2-3:1; 15-40%). The TiC14-promoted reaction of 4b with 9a gave 11a with excellent selectivity (16: 1). In contrast, the MgBr2·OEt2-promoted reaction of 4b with 9a gave the anti-Felkin adducts exclusively as a 3:1 mixture of syn (13a)/anti (14a) diastereomers. Similar aldol reactions of 3 with the cis and trans isomers of 4-(methoxy)methoxytetrahydro-2H-thiopyran-3-carboxaldehyde (9b and 9c) were examined to probe the influence of the ketal protecting group in 9a on the observed aldol diastereoselectivity. The results are rationalized by applying Evans' stereochemical model for merged 1,2- and 1,3-asymmetric induction (nonchelation), with the exception of the MgBr2· OEt2-promoted reactions of 4b with 9a, 9b, and 9c, which are accommodated by assuming chelation control. Comparison of the reactions of 9a, 9b, and 9c suggests that the ketal group in 9a uniquely allows high levels of either Felkin or anti-Felkin selectivity to be achieved.
Synthesis and reduction kinetics of sterically shielded pyrrolidine nitroxides
Paletta, Joseph T.,Pink, Maren,Foley, Bridget,Rajca, Suchada,Rajca, Andrzej
supporting information, p. 5322 - 5325 (2013/01/15)
A series of sterically shielded pyrrolidine nitroxides were synthesized, and their reduction by ascorbate (vitamin C) indicate that nitroxide 3, a tetraethyl derivative of 3-carboxy-PROXYL, is reduced at the slowest rate among known nitroxides, i.e., at a 60-fold slower rate than that for 3-carboxy-PROXYL.