Diastereoselectivity in the rhodium-catalyzed hydroformylation of (+)(R)-1-phenylethyl vinyl ether

The degree of diastereoselectivity in the rhodium-catalyzed hydroformylation of (+)(R)-1-phenylethyl vinyl ether is much higher than that in the hydroformylation of the related olefin, 4-phenyl-1-pentene.     

Synthesis of 1-(2-naphthyl)dihydro- and 1-(2-naphthyl)-2-thiodihydrouracils and their transformations

1-(2-Naphthyl)dihydro- and 1-(2-naphthyl)-2-thiodihydrouracils were obtained from N-(2-naphthyl)--alanine derivatives. The thiodihydrouracil was converted to a dihydrouracil. Bromination of 1-(2-naphthyl)dihydrouracil gave (1-bromonaphthyl)dihydrouracil. 1-(2-Naphthyl)-2-oxo-, 1-(2-naphthyl)-2-thio-. and 1-(1-bromo-2-naphthyl)-2-oxohexahydro-pyrimidines were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii. No. 12, pp. 1695–1697, December, 1971.     

Pyrroles from ketoximes and acetylene. 23. 2-(1-naphthyl)- and 2-(2-naphthyl)pyrroles and their 1-vinyl derivatives

2-(1-Naphthyl)- and 2-(2-naphthyl)pyrroles and their 1-vinyl derivatives were synthesized in 22–64% yields by the reaction of 1- and 2-acetylnaphthalene oximes with acetylene at both atmospheric pressure and elevated pressures in an alkali metal hydroxide-dimethyl sulfoxide system.See [1] for communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1351–1353, October, 1982.     

1-benzoyl-2-(2-naphthyl)-selenourea

During our synthesis of N-benzoyl-N'-aryl selenourea derivatives, we isolated the title compound. One of them was selected optically for the diffraction study. The crystal belongs to the Monoclinic space group P21/n, Mr = 353.27, a = 11.073(1)A, b = 5.745(1) A, c = 24.356(5) A, β= 92.10 (1) °, V= 1548.3 (4) A3, Z = 4, Dx=1.515 Mg/m3, λ (Mo Kα )=0.71073 A, θ = 1.67-25, μ= 2.428 mm-1 , T = 296 (2) K.View of the molecule showing the labeling of the non-H atoms are described as:The selenourea and thiourea have analogous structure, a few literatures have reported the crystal of N-benzoyl-N'-aryl thiourea derivative1,2. In the reported crystal structure of N-benzoyl-N'-aryl thiourea derivative, there is a intermolecular hydrogen bond between the carbonyl O and H atom on N', in each -C(O)-NH-N'H- moiety, forming a planar six-membered ring. In this title compound,[2.654(2)A], C (8), N (1) and C (7)l.In the crystal structure of N-benzoy-N'-aryl thiourea derivative, there have a two dimensional With the intramolecular hydrogen bond [2.654(2)A] they form the planar four-membered ring between every molecular. The atom of Se dose not link the moleculars like the S atom of N-benzoyl-N'-aryl thiourea derivative, and it is only out of six-membered ring, which forms by N (2)H…O, C (8), N (1) and C (7).     

Acetylation of 2-(1-naphthyl)thiophene

Acetylation of 2-(1-naphthyl) thiophene with acetyl chloride in the presence of SnCl₄, or with acetic anhydride in the presence of H₃PO₄ gives 5-aceto-2-(1-naphthyl) thiophene. 5-Ethyl-2-[1-(3, 4-dihydronaphthyl)] thiophene, 5-ethyl-2-(1-naphthyl) thiophene and 3, 4-diacetoxymercuri-5-ethyl-2-(1-naphthyl) thiophene are now synthesized and characterized.     

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.     

Nitro derivatives of 2-(1-naphthyl) thiophene

2-[1-(3, 4-Dihydronaphythyl)]thiophene, 2-(1-naphthyl)thiophene, 3, 4, 5-triacetoxymercuri-, 3, 4-diacetoxymercuri-5-nitro-, 4, 5-diacetoxymercuri-3-nitro-2-(1-naphthyl)thiophenes and 3, 3, 4-triacetoxymercuri-2[1-(4-nitronaphthyl)]thiophene are synthesized and characterized. Nitration of 2-(1-naphthyl)thiophene with copper nitrate in acetic anhydride leads to formation of two isomeric mono-nitro derivatives, 4-nitro- and 5-nitro-2-(1-naphthyl)thiophene.     

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.     

Enantioselective synthesis of axially chiral 1-(1-naphthyl)isoquinolines and 2-(1-naphthyl)pyridines through sulfoxide ligand coupling reactions

Racemic 1-(1′-isoquinolinyl)-2-naphthalenemethanol rac-12 was prepared through a ligand coupling reaction of racemic 1-(tert-butylsulfinyl)isoquinoline rac-7 with the 1-naphthyl Grignard reagent 10. Resolution of rac-12 was achieved through chromatographic separation of the Noe-lactol derivatives 14 and 15, providing (R)-(−)-12 of >99% ee and (S)-(+)-12 of 90% ee. The ligand coupling reaction of optically enriched sulfoxide (S)-(−)-7 (62% ee) with Grignard reagent 10 furnished rac-12, with the absence of stereoinduction resulting from competing rapid racemisation of the sulfoxide 7. Reaction of optically enriched (S)-(−)-7 with 2-methoxy-1-naphthylmagnesium bromide was also accompanied by racemisation of the sulfoxide 7, and furnished optically active (+)-1-(2′-methoxy-1′-naphthyl)isoquinoline (+)-3b in low enantiomeric purity (14% ee). The absolute configuration of (+)-3b was assigned as R using circular dichroism spectroscopy, correcting an earlier assignment based on the Bijvoet method, but in the absence of heavy atoms. Optically active 2-pyridyl sulfoxides were found not to undergo racemisation analogous to the 1-isoquinolinyl sulfoxide 7, with the ligand coupling reactions of (R)-(+)- and (S)-(−)-2-[(4′-methylphenyl)sulfinyl]-3-methylpyridines, (R)-(+)-17 and (S)-(−)-17, with 2-methoxy-1-naphthylmagnesium bromide providing (−)- and (+)-2-(2′-methoxy-1′-naphthyl)-3-methylpyridines, (−)-18 and (+)-18, in 53 and 60% ee, respectively. The free energy barriers to internal rotation in 3b and 18 have been determined, and the isoquinoline (R)-(−)-12 examined as a ligand in the enantioselectively catalysed addition of diethylzinc to benzaldehyde; (R)-(−)-12 was also converted to (R)-(−)-N,N-dimethyl-1-(1′-isoquinolinyl)-2-naphthalenemethanamine (R)-(−)-19, and this examined as a ligand in the enantioselective Pd-catalysed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate.     

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.