Synthesis of 1-(α-phenylethyl)azetidin-2-ones

Phase-transfer catalyzed cyclization of racemic and optically active N-substituted -aminoacids has given racemic and optically active 2-azetidinones, the spatial structures of which have been established by NMR spectroscopy. The original -aminoacids were obtained by adding -phenylethylamine to substituted acrylic acids.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1644–1647, December, 1984.     

Asymmetric synthesis of 2-substituted piperidines using a multi-component coupling reaction: rapid assembly of (S)-coniine from (S)-1-(1-phenylethyl)-2-methyleneaziridine

(S)-Coniine is made using a reaction which assembles the piperidine ring by the sequential formation of four new chemical bonds and installs the C-2 stereogenic centre with high levels of diastereocontrol (90% de).     

Catalyst free conjugate addition of indoles and pyrroles to nitro alkenes under solvent free condition (SFC): an effective greener route to access 3-(2-nitro-1-phenylethyl)-1H-indole and 2-(2-nitro-1-phenylethyl)-1H-pyrrole derivatives

Catalyst free conjugate addition of reactive hetero aromatics (pyrrole and indoles) to nitro alkenes under solvent free condition is described. This method provides several advantages, such as operational simplicity, solvent-free conditions and good yields of products. Also it is environmentally friendly and more cost effective alternative to existing protocols.     

Some reactions of 1-methyl-(2-phenylethyl)-1,2,3,4-tetrahydropyridines with organic azides. Synthesis of 1-methyl-(2-phenylethyl)piperidylidene-2-sulfonamides

The 1,3-dipolar cycloaddition reaction of 1-methyl- and 1-(2-phenylethyl)-1,2,3,4-tetrahydropyridines 7 with organic azides 8 afforded the respective 1-substituted-piperidylidene-2-sulfon(cyan)amides 9. Nitration of the 1-(2-phenylethyl) analogue 9o yielded the 1-[2-(4-nitrophenyl)ethyl] derivative 9r which on reduction with palladium-on-charcoal and hydrazine gave the 1-[2-(4-aminophenyl)ethyl] analogue 9s.     

Six new 2-(2-phenylethyl)chromones from Agarwood

Six new chromones, 6-methoxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyllchromone (2), 6,8-dihydroxy-2-(2-phenylethyl)chromone (3), 6-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (4), 6-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (5), 7-hydroxy-2-(2-phenylethyl)chromone (6), and 6-hydroxy-7-methoxy-2-(2-phenylethyl)chromone (7) were isolated from the ether extract of agarwood in addition to a known compound, 2-(2-phenylethyl)chromone or flidersiachromone (1). Their structures were determined by spectroscopic methods including UV, IR, and NMR spectral data and comparisons with the calculated values using the hydroxyl and methoxyl substituent increments of the chromone ring.     

Facile Synthesis of 5-Hydroxy-2-（2-phenylethyl）chromone

5-Hydroxy-2-(2-phenylethyl)chromone(1) was synthesized from 2,6-dihydroxyacetophenone(7) obtained via four-steps resorcinol-reacting with phenylpropionic acid,the procedures involved are Baker-Venkataraman rearrangement and cyclization which are easy to conduct,the overall yield is 32%.     

Stereospecific synthesis of N-(1-phenylethyl)-2,4,5-triphenyloxazolidines

Treatment of the diastereoisomeric N-(1-phenylethyl)-1,2-diphenyl-2-aminoethanols with benzaldehyde yields stereospecifically N-(1-phenylethyl)-2,4,5-triphenyloxazolidines with four chiral centers. The configurations of these oxazolidines are established through their ring-opening reactions with methylmagnesium iodide and subsequent oxidation with lead tetracetate.     

Asymmetrical alkylation of 1-[(s)-α-phenylethyl]-azethidinone-2

The methylation of the lithium derivative of azethidinone-2 which has a chiral substituent at the nitrogen atom is asymmetrical and leads, with an optical yield of 35%, to diastereomeric 3-methylated azethidinones-2. The reaction of these compounds with Na in liquid ammonia gives enantiomeric 3-methylazethidinones which confirms that an asymmetrical synthesis has taken place.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 607–611, May, 1986.     

Efficient preparation of (1′R)-(−)-1-(2′-hydroxy-1′-phenylethyl)piperidin-2-one: synthesis of (2′S,3R)-(+)-stenusine

An efficient oxidation of (2′R)-(−)-2′-phenyl-2′-(piperidin-1-yl)ethanol 2 with bromine to generate the corresponding piperidin-2-one 3 in 96% is described. In addition, starting from 3, (2′S,3R)-(+)-stenusine 8 was synthesized in 70% overall yield. The X-ray analysis of piperidine 6·HCl is also reported.