22172-84-5Relevant academic research and scientific papers
Piperidine and azetidine formation by direct cyclization of diols with N-nonsubstituted sulfonamide under the Mitsunobu conditions utilizing (cyanomethylene)tributylphosphorane (CMBP) and its application to the synthesis of lupinine
Hamaguchi, Takumi,Hishida, Hideyuki,Horikawa, Mitsuyo,Inai, Makoto,Kaku, Hiroto,Kitamura, Kei,Kubo, Akiko,Sonoda, Yuhei,Taniguchi, Yuri,Tsunoda, Tetsuto
, p. 1525 - 1535 (2020/01/28)
(Cyanomethylene)tributylphosphorane (CMBP) can promote the Mitsunobu reaction of 1,3- and 1,5-diols with N-nonsubstituted sulfonamides, such as tosylamide (TsNH2) and 3,3-dimethoxypropylsulfonamide (DimpsNH2), to prepare azetidine and piperidine ring systems directly. Utilizing this methodology, lupinine, a biologically active piperidine alkaloid, was synthesized.
Removal of benzotriazole moiety from 2-[2-aryl-2-(benzotriazol-1- yl)ethyl]tetrahydro-2H-pyrans and 2-[2-aryl-2-(benzotriazol-1-yl)ethyl]-5- (methyl)tetrahydrofurans using lithium naphthalene radical anion
Kang, Yoon Ho,Kim, Kyongtae
, p. 4271 - 4286 (2007/10/03)
In order to see the effects of non-bonding electrons in oxygen atoms on the cleavage of a bond between N-1 of the benzotriazole moiety and the a- carbon atom bonded to N-1 by lithium (6a) and sodium naphthalenides (6b), 2- [2-aryl-2-(benzotriazol-1-yl)ethyl]tetrahydro-2H-pyrans (4), and 2-[2-aryl- 2-(benzotriazol-1-yl)ethyl]-5-(methyl)tetrahydrofurans (5), and 1- (benzotriazol-1-yl)-1,2-diphenylethane (7) were prepared. The reactions of 4 with 6a in THF at room temperature gave 2-(2-arylethyl)tetrahydro-2H-pyrans (12) in 45 to 62 % yields along with benzotriazole and naphthalene. In addition, 2-(benzoylethyl)tetrahydro-2H-pyran (15) (12 %) was obtained only from the reaction of 2-[2(benzotriazol-1-yl)-2-(phenyl)ethyl]tetrahydro-2H- pyran. Similarly, the reactions of 5 with 6a under the same conditions afforded 2-(2-arylethyl)-5-(methyl)tetrahydrofurans (30) in 59 to 77 % yields along with the foregoing byproducts. Interestingly, the reaction of 7 with 6a under the same conditions gave deoxybenzoin (24) in 41% yield along with the foregoing byproducts. The results suggest that 6a acts as a single electron- transfer agent in the reactions of 4 and 5, and a base in the reaction ofT. It is envisaged that for the former, Li+ participates in the formation of a six-membered cyclic intermediate so that cleavage of a-C-N-1 bond is facilitated to give eventually 12 and 22, whereas for the latter, 6a abstracts a proton from a-C bonded to N-1 to generate a carbanion 19, which extrudes a nitrogen molecule to generate a new phenyl carbanion 20. Protonation leading to mono iminobenzoin 21, followed by hydrolysis gives 15. The formation of 24 can be explained based on the same mechanism as for the latter reaction.
Baker's yeast reduction of arylalkyl and arylalkenil γ- and δ-keto acids
Aquino, Mario,Cardani, Silvia,Fronza, Giovanni,Fuganti, Claudio,Fernandez, Rosalino Pulido,Tagliani, Auro
, p. 7887 - 7896 (2007/10/02)
γ- and δ-Lactones 5, 6, 13, 14, 15 and 16 were synthesized via baker's yeast reduction of the corresponding keto acids 3, 4 and 9-12. The enantioselectivity of the reduction is strongly dependent on the nature of the keto acid; the δ-lactones ware always obtained in an ee% higher than the γ-lactones and ranging from 70% to 100%.
Reaction of Acetals with Grignard Reagents
Ishikawa, Hiroshi,Mukaiyama, Teruaki,Ikeda, Shigeru
, p. 776 - 780 (2007/10/02)
The reaction of dialkyl acetals derived from α,β-unsaturated aldehydes with Grignard reagents using TiCl4 in THF afforded the cross coupling products, allyl ethers, in high yields.The TiCl4-promoted reaction of alkyl 2,4-dichlorophenyl acetals, synthesized from 3,4-dihydro-2H-pyran or ethyl vinyl ether and 2,4-dichlorophenol, with Grignard reagents in THF at low temperature afforded the corresponding unsymmetrical ethers in high yields.When alkyl 2,4-dichlorophenyl acetals, synthesized from aromatic aldehyde or vinyl ethers and 2,4-dichlorophenol, were treated with Grignard reagents in benzene or toluene at room temperature in the absence of TiCl4, the cross coupling reaction took place and the corresponding ethers were isolated in good yields.
