IODODECARBOXYLATION OF α-CARBOXYLATE, α-CINNAMOYL KETENE CYCLIC DITHIOACETALS

ABSTRACT

The iododecarboxylation reaction of α-carboxylate, α-cinnamoyl ketene cyclic dithioacetals 2 was successfully performed with iodine as halogenation reagent and in water insensitive media. This reaction provides a mild and efficient method for the preparation of α-iodo, α-cinnamoyl ketene cyclic dithioacetals 3 which are important kinds of potential new intermediates to be valued.     

α－OXOKETENE CYCLIC DITHIOACETALS CHEMISTRY ──REACTION OF α，α－DIOXO（ESTER）KETENE CYCLIC DITHIOACETALS WITH BUTANONE

α－ＯＸＯＫＥＴＥＮＥＣＹＣＬＩＣＤＩＴＨＩＯＡＣＥＴＡＬＳＣＨＥＭＩＳＴＲＹ──ＲＥＡＣＴＩＯＮＯＦα，α－ＤＩＯＸＯ（ＥＳＴＥＲ）ＫＥＴＥＮＥＣＹＣＬＩＣＤＩＴＨＩＯＡＣＥＴＡＬＳＷＩＴＨＢＵＴＡＮＯＮＥ￥ＺａｉＭｉｎｇＺＨＵ；ＹｏｎｇＴｉｎｇＸ...     

ETEREOSPECIFIC SYNTHESIS OF α-D-FRUCTOFURANOSIDES——SYNTHESIS OF THE OLIGO-FRUCTAN DIASTEREOISOMERS

α-fructofuranosides were stereospecifically synthesized from2-O-Ac-1,3,4,6-O-tetra-benzoylfructose by employing TMSOTf as a catalyst.Meanwhile,one diastereoisomer derivative of sucrose and two of fructanoligomers were synthesized.The structure of all products were confirmed by~(13)C-NMR and ~1H-NMR spectra.     

CONDENSATION REACTION OF α-AROYL-α-ACETYL KETENE CYCLIC DITHIOACETALS WITH AROMATIC ALDEHYDES

As a versatile three-carbon syntho,α-oxoketene cyclic acetals 1 have been applied in many fields. In order to study the structure and application of 1, we performed that α-aroyl-α-acetyl ketene cyclic dithioacetals 2 or 3 condensed with aromatic aldehydes catalyzed by sodium ethoxide and fifteen new condensation products 4 and 5 were obtained.     

FIRST SYNTHESIS OF SINGLE AND MIXED α-OXO KETENE DITHIOACETALS FROM ACTIVE METHENYL PRECURSORS

ABSTRACT

β-Dioxodithioate were produced easily from active methenyl precursors, carbondisulfide and RX with potassium carbonate as base. By a selective basic assistant cleavage of a carbon–carbon bond at the β-dicarbonyl unit of β-dioxodithioate and the subsequent alkylation with RX/R′X in situ, single or mixed α-oxo ketene dithioacetals were obtained in good yields.     

SYNTHESIS OF 3-BUTYLIDENE-5-HYDROXYPHTHALIDE

3-Butylidene-5-hydroxyphthalide(1)was prepared from 4-hydroxy-benzoic acid(2).     

SYNTHESIS OF α-AND β-OLEFINIC DITHIOESTERS - REACTIONS WITH GRIGNARD REAGENTS - SYNTHESIS OF ARTEMISIA KETONE

Abstract

A new synthesis of dithioesters, starting from phenylisothiocyanate is described (scheme I) and this method is convenient for the preparation of β-olefinic dithioesters (e. g. 1, scheme II).     

REACTIONS WITH PHOSPHACUMULENES: SYNTHESIS OF PYRAN DERIVATIVES FROM THE REACTION OF N-PHENYLIMINOKETENYLIDENE TRIPHENYL-PHOSPHORANE WITH α,β-UNSATURATED CARBONYL COMPOUNDS

Abstract

2-Benzylidene-1,3-indanedione (2), 4-benzylidene-1,2-diphenyl-3,5-pyrazolidenedione (4) and/or 5-benzylidenebarbituric acid (6) can be converted by reaction with N-phenyliminoketenylidene triphenylphosphorane (1) into pyransubstituted phosphoranes 3, 5 and 7. The structure of the new cyclic imino-phosphoranes 3, 5 and 7 was confirmed on the basis of elemental analysis and spectral studies. Moreover, when Wittig reaction was carried out on the pyran compound 7, using p-nitrobenzaldehyde, the new olefin 8 was isolated.     

SYNTHESIS OF NEW α-KETOPHOSPHONATES

Abstract

Using the Arbuzov reaction, asymmetrical or symmetrical benzyl α-ketophosphanates can be synthesized. In the case of symmetrical benzyl α-ketophosphonates, it was observed that the modification of benzyl groups influences the yield of the Arbuzov reaction.     

SYNTHESIS AND STRUCTURE OF ADDUCT OF 1, 9-DIHYDRO-8,9-DIPHENYL-1, 2, 4-TRIAZOLO [4, 3-d] 1, 2, 4-TRIAZINE-3, 5-DITHIONE WITH TRIETHYLAMINE

<正> C16H13N5S2· (C2H5)3N: Mr = 440. 64, monoclinic, space group C2/c with a = 18.956(7)(?), b = 12. 866(7)(?), c = 20. 830(9)(?) , β=115. 63(3)°; Z=8; V = 4580(7)(?)3; Dc = 1. 278gcm-3; F (000) = 1872, μ= 2. 423cm-1 (MoKa). Final R is 0. 069. C16H13N5S2is non-planar with two rings, a five-member and a six-member with conformations of envelope and twist boat forms respectively, and the two substituted phenyl groups are in equatorial and axial positions.     

SYNTHESIS OF α-AMINOORTHOESTERS FROM O-TOSYLHYDROXIMATES

ABSTRACT

The abstraction of the acid hydrogen of O-tosylhydroximates 1 by sodium ethylate, then nucleophilic attack of the excess of sodium ethylate at the more hindred carbond atom of azirine 2 and aziridine 3 intermediates to give the α-aminoorthoesters (35–45% yields). The α-aminoorthoester 4a is transformed into α-iminoorthoesters 5a (63% yield) and α-amidoorthoester 6a (65% yield).     

SYNTHESIS OF THE C-DISACCHARIDE α-C(1→3)-L-FUCOPYRANOSIDE OF N-ACETYLGALACTOSAMINE[1]

Radical C-glycosidation of racemic 5-exo-benzeneselenyl-6-endo-chloro-3-methylidene-7-oxabicyclo[2.2.1]heptan-2-one ((±)-2) with α-acetobromofucose (3) provided a mixture of α-C-fucosides that were reduced with NaBH₄ to give two diastereomeric alcohols that were separated readily. One of them ((?)-6) was converted into (?)-methyl 2-acetamido-4-O-acetyl-2,3-dideoxy-3-C-(3′,4′,5′-tri-O-acetyl-2′,6′-anhydro-1′,7′-dideoxy-α-L-glycero-D-galacto-heptitol-1′-C-yl)-α -D-galactopyranuronate ((?)-11) and then into (?)-methyl 2-acetamido-2,3-dideoxy-3-C-(2′,6′-anhydro-1′,7′-dideoxy-α-L-glycero-D-galacto-heptitol-1′-C-yl)-β -D-galactopyranoside ((?)-1), a new α-C(1→3)-L-fucopyranoside of N-acetylgalactosamine. Its ¹H NMR data shows that this C-disaccharide (α-L-Fucp-(1→3)CH₂-β-D-GalNAc-OMe) adopts a major conformation in solution similar to that expected for the corresponding O-linked disaccharide, i.e., with antiperiplanar σ(C-3′,C-2′) and σ(C-1′,C-3) bonds.     

THE SYNTHESIS OF Ti-ZSM-5 STARTING WITH DE-[B]ZSM-5

ＴＨＥＳＹＮＴＨＥＳＩＳＯＦＴｉ┐ＺＳＭ┐５ＳＴＡＲＴＩＮＧＷＩＴＨＤＥ┐［Ｂ］ＺＳＭ┐５ＬｉＭｉｎｇｆｅｎｇ，ＧｕｏＸｉｎｗｅｎ，ＷａｎｇＸｉａｎｇｓｈｅｎｇ＊（ＩｎｓｔｉｔｕｔｅｏｆＩｎｄｕｓｔｒｉａｌＣａｔａｌｙｓｔ，ＤａｌｉａｎＵｎｉｖｅｒｓ...     

SYNTHESIS OF α-AZIDO-2′-HYDROXYCHALCONES FROM CHALCONE DIBROMIDES WITH AZIDE ION

ABSTRACT

The reaction of the 2′-hydroxychalcone dibromides with azide ion was found to afford various products such as α-azido-2′-hydroxychalcones, flavones, aurones, isoxazoles or the parent chalcones depending on the substituent pattern of the substrate. Efficient transformation of α-azido-2′-hydroxychalcones to 3-amino-2-substituted chromones was also demonstrated.     

THE HYDROSILYLATION REACTION OF LADDERLIKE POLYVINYLSILSESQUIOXANE WITH 1, 1, 3, 3-TETRAMETHYLDISILOXANE

The hydrosilylation reaction of ladderlike polyvinylsilsesquioxane (Vi-T)with 1, 1, 3, 3-tetramethyldisiloxane (H- MM ) catalyzed by dicyclopentadienyl-dichloroplat-inium (Cp_2PtCl_2) was carried out well in tetrahydrofuran (THF) to produce a soluble whitesolid. This product was characterized by IR, ~1H-NMR, ~(13)C-NMR, ~(29)Si-NMR, DSC, X-raydiffraction method, gel permeation chromatography (GPC), vapour pressure osmometry(VPO), atomic force microscopy (AFM) and molecular simulation. These results provethat the product contains nanoscale tubular structure.     

SYNTHESIS OF N,N''''-DISUBSTITUTED MONOTHIOXAMIDE AND STUDY OF THEIR REACTIONS WITH DIAMINES

In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds were synthesized by using these reactions.     

SYNTHESIS AND TAUTOMERISM OF KETENE N,O-ACETALS WITH BENZOXAZOLINE RING

Benzoxazoline ring substituted ketene N,O-acetals 3 were synthesizedby the reaction of ketene S,S-acetals 2 with 2-aminophenol.Thetautomeric equilibrium of some 3 was also observed.     

REACTION OF ORGANODILITHIUM REAGENT WITH α,α''''-DIHALO-o-XYLENE

ＲＥＡＣＴＩＯＮＯＦＯＲＧＡＮＯＤＩＬＩＴＨＩＵＭＲＥＡＧＥＮＴＷＩＴＨα，α'－ＤＩＨＡＬＯ－ｏ－ＸＹＬＥＮＥ￥ＨａｉＨｏｎｇＨＵＡＮＧ（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｅｒｉａＭｅｄｉｃａ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＭｅｄｉｃａｌＳｃｉｅｎｃｅ?..     

SYNTHESIS OF MESOGENIC POLYESTERS WITH 2-DICHLOROMETHYLHYDROQUINONE MOIETIES

A series of novel mesogenic polyesters with 2-dich1oromethylhydroquinone moieties weresynthesized by polycondensation of the novel diacyl chloride monomer 2-dichloromethyl-1, 4-bis (4'-chloroformylbenzoyl) oxybenzene-(I) with α,ω-polymethylenediols including ethyleneglycol, 1, 4-butanediol, 1, 6-hexanediol and 1, 10-decanediol. The diacyl chloride monomerwas synthesized by simultaneous transformations of both the carboxy and formaldehydegroups of 2-formyl-1, 4-bis (4'-carboxybenzoyl) oxybenzene into acyl chloride anddichloromethyl groups respectively. The syntheses of the monomer (I) and the polymers werereported.