摘要:

AbstractThe conversion of 3‐methyl‐4‐benzyl‐4‐chloro‐2‐pyrazolin‐5‐one10bwas catalyzed by a mixture of potassium fluoride and alumina to givesyn‐(methyl, benzyl)bimane6(62%) without detectable formation of theantiisomer,A6[a 1 : 1 mixture (87%) of the isomers6andA6was obtained when the catalyst was potassium carbonate]. In a similar reactionsyn‐(methyl,carboethoxymethyl)bimane7(15%) with theantiisomerA7(36%) was obtained from 3‐methyl‐4‐carboethoxymethyl‐4‐chloro‐2‐pyrazolin‐5‐one10c.syn‐(Methyl, β‐acetoxyethyl)bimane8(70%) was obtained from 3‐methyl‐4‐β‐acetoxyethyl‐4‐chloro‐2‐pyrazolin‐5‐one10d(potassium carbonate catalysis) and was converted by hydrolysis tosyn‐(methyl, β‐hydroxyethyl)bimane9(40%). Acetyl nitrate (nitric acid in acetic anhydride) convertedanti‐(amino,hydrogen)bimane11toanti‐(amino,nitro)bimane15(91%),anti‐(methyl,hydrogen)bimane13toanti‐(methyl,nitro)(methyl,hydrogen)bimane16(57%), and degradedsyn‐(methyl,hydrogen)bimane12to an intractable mixture. Treatment with trimethyl phosphite convertedsyn‐(bromomethyl,methyl)bimane17tosyn‐(dimethoxyphosphinylmethyl,methyl)bimane18(78%) that was further converted tosyn‐(styryl,methyl)bimane19(29%) in a condensation reaction with benzaldehyde. Treatment with acryloyl chloride convertedsyn‐(hydroxymethyl,methyl)bimane20to its acrylate ester21(22%). Stoichiometric bromination ofsyn‐(methyl,methyl)bimane1gave a monobromo derivative that was converted insituby treatment with potassium acetate tosyn‐(acetoxymethyl,methyl)(methyl,methyl)bimane47. N‐Amino‐μ‐amino‐syn‐(methylene,methyl)bimane24(68%) was obtained from a reaction between the dibromide17and hydrazine. Derivatives of the hydrazine24included a perchlorate salt and a hydrazone25derived from acetone. Dehydrogenation ofsyn‐(tetramethylene)bimane26by treatment with dichlorodicyanobenzoquinone (DDQ) gavesyn‐(benzo,tetramethylene)bimane27(58%) andsyn‐(benzo)bimane28(29%). Bromination of the bimane26gave a dibromide29(92%) that was also converted by treatment with DDQ tosyn‐(benzo)bimane28. Treatment with palladium (10%) on charcoal dehydrogenated 5, 6, 10, 11‐tetrahydro‐7H,9H‐benz [6, 7] indazol [1, 2a]benz[g]indazol‐7,9‐dione35tosyn‐(α‐naphtho)bimane36(71%). The bimane35was prepared from 1,2,3,4‐tetrahydro‐1‐oxo‐2‐naphthoate37by stepwise treatment with hydrazine to give 1,2,4,5‐tetrahydro‐3H‐benz[g]indazol‐3‐one38, followed by chlorine to give 3a‐chloro‐2,3a,4,5‐tetrahydro‐3H‐benz[g]indazol‐3‐one39, and base. Dehydrogenation over palladium converted the indazolone34to 1H‐benz[g] indazol‐3‐ol36. Helicity for the hexacyclicsyn‐(α‐naphtho)bimane36was confirmed by an analysis based on molecular modeling.The relative efficiencies (RE) for laser activity in the spectral region 500–530 nm were obtained for 37syn‐bimanes by reference to coumarin 30 (RE 100): RE>80 forsyn‐bimanes3, 5, 18, and μ‐(dicarbomethoxy)methylene‐syn‐(methylene,methyl)bimane22: RE 20–80: forsyn‐bimanes1,2,4,20,24,26, and μ‐thia‐syn‐(methylene,methyl)bimane50: and RE 0‐20 for 26syn‐bimanes. The bimane dyes tended to be more photostable and more water‐soluble than coumarin 30. The diphosphonate18in dioxane showed laser activity at 438 nm and in water at 514 nm. Pre

ISSN:1042-7163    

DOI:10.1002/hc.520010302

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe alkylation‐metalation reaction of phosphoric esters depends on the way the lithium reagent has been prepared. With salt‐containing methyllithium (LiBr or LiI), the alkylation is never complete. On the contrary, with salt‐free methyllithium, the alkylation is completed at – 10°C. This reaction is performed independently of the substituents at the phosphor

ISSN:1042-7163    

DOI:10.1002/hc.520010303

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reactions of 13 aliphatic ketones with tellurium tetrachloride has been studied with proton, carbon‐13, and tellurium‐125 NMR. Tellurium tetrachloride adds electrophilically to the α‐carbon of the enol to form ketonyl tellurium trichlorides. Unsymmetric ketones gave mixtures of isomeric ketonyl tellurium trichlorides. Steric hindrance determines which ketonyl tellurium trichlorides form. Except for the ketonyl tellurium trichloride from 2‐butanone, tellurium reacts preferentially with the least substituted α‐carbon. Six methyl alkyl ketones also yielded appreciable amounts of diketonyl tellurium dichlorides. In all diketonyl tellurium dichlorides, tellurium is bonded to less hindered methyl

ISSN:1042-7163    

DOI:10.1002/hc.520010304

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractLigand coupling of (E)‐ and (Z)‐styryl 2‐pyridyl sulfoxides with methylmagnesium bromide gave (E)‐and (Z)‐2‐styrylpyridine, respectively in a stereospecific manner. A number of (E)‐2‐styrylpyridine derivatives were prepared by the coupling reaction. Methyl styryl sulfoxide and 2,2′‐bipyridyl were obtained as by‐products. The mechanism of the reaction is discussed based on quantitative ana

ISSN:1042-7163    

DOI:10.1002/hc.520010305

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe reaction of catechols with bismuth (III) acetate in acetic acid solution provides an easy access to the polymeric bismuth catecholate acetate (1), 4‐tert˙ butylcatecholate hydroxide (2), and 3,5‐di‐tert ˙ butylcatecholate hydrox

ISSN:1042-7163    

DOI:10.1002/hc.520010306

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThioacetals and thioketals were readily cleaved to carbonyl compounds in excellent yields by treatment witht‐butyl thionitrite at ca. 0°C in acetonitrile under mild conditions. The conversion of thioketals to the ketones appears to be initiated via nitrosation on two sulfur atoms of the thioketals, followed by intramolecular transfer of nitroso oxyg

ISSN:1042-7163    

DOI:10.1002/hc.520010307

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractReaction betweenO,O‐diethyl‐S‐phenyl phosphorothiolate and lithium dialkylamides results in the displacement of the PhS substituent by the R2N group. With Grignard reagents, the same substrate gives products of the nucleophilic substitution at both the phosphorus and the sulfur

ISSN:1042-7163    

DOI:10.1002/hc.520010308

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractDi‐n‐butyl telluride, 2‐bromoacetylisobutylamide (or 2‐bromoacetylpiperidide) react directly with saturated or α,β‐unsaturated aldehydes at room temperature in the presence of potassium carbonate(s) to afford (2E)‐, or (2E, 4E)‐unsaturated carboxylic acid amides, respectively, in excellent yields with high E st

ISSN:1042-7163    

DOI:10.1002/hc.520010309

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe title compound was prepared by sulfurization of a 1‐phosphaallene and its x‐ray structure analysis showed the following notable features of the thiaphosphirane ring: P‐S = 2.101(2), P‐C = 1.770(5) and S‐C = 1.767(5) Å (remarkably short), and ∠SPC = 53.5(2), ∠PSC = 53.6(2) and

ISSN:1042-7163    

DOI:10.1002/hc.520010310

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe literature reveals that the structures of four unusual oxaphosphetanes have been established by x‐ray diffraction studies, and the structure of one mythical oxaphosphetane (6) has been deduced by theoretical calculations. We have used these known structures to calibrate the MMX87 force field, the only necessary modification being the stretching term for the P‐O bond. The bond length, 1o, was set at 1.80Å, which is an “average” of the P‐O axial bond distances of the stable oxaphosphetanes. The AMPAC (Ver. 1.0) molecular orbital package utilizing the MNDO hamiltonian was also applied to the same problem, starting with the minimized geometries of the modified MMX87 force field. Fixed bond lengths and full minimizations were performed. The computed geometries of the four‐member ring of each of the four oxaphosphetanes of known structures were found to be in very good agreement with the values obtained by x‐ray diffraction. Furthermore, the method was applied to the mythical oxaphosphetane, and the results of MMX87 and MNDO calculations were found to be in very good agreement with the results of ab initio calculations. The MMX force field and the MNDO semiempirical method have been used to calculate the geometries and the steric energies (or heats of formation) of diastereomeric oxaphosphetanes formed in a theoretically real W

ISSN:1042-7163    

DOI:10.1002/hc.520010311

出版商:VCH Publishers, Inc.    

年代:1990

数据来源: WILEY