Diorganostannylenes : III. Formation of dimethylstannylene from 1,1-dimethyl-2,3,4,5-tetraphenyl-1-stannacyclopentadiene and acetylenes

Dimethylstannylene, (CH₃)₂Sn:, was formed transiently in the reaction of 1,1-dimethyl-2,3,4,5-tetraphenyl-1-stannacyclopentadiene (stannole) with dimethyl acetylenedicarboxylate or phenylacetylene. When this reaction was carried out in the presence of n-butyl bromide, dimethylstannylene inserted into the CBr bond of n-butyl bromide to give n-butyldimethyltin bromide in 12% yield, but most of the dimethylstannylene was captured by dimethyl acetylenedicarboxylate to give a complex. The complex was also produced in the photolytic reaction of the dimethyltin polymer, [(CH₃)₂Sn]_m, with dimethyl acetylenedicarboxylate. With phenylacetylene, dimethylstannylene did not give a similar complex, but polymerized to give the dimethyltin polymer.     

2-Benzopyrylium salts. 27. Formation of substituted chrysenes from 1-methyl-2-benzopyrylium salts

1-Methyl-2-benzopyrylium salts with a free position of the heteroring primarily form substituted chrysenes. In alkaline media this process does not proceed through the intermediate formation of 1,5-diketones.For Communication 26, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1472–1476, November, 1984.     

Polymers from 12 α-hydroxymethylabiet-7,8-enoic acid and vinyl 12 α-hydroxymethylabiet-7,8-enoate

12 α-Hydroxymethylabiet-7,8-enoic acid has been homopolymerized by melt condensation, and a partially crystalline polyester has been obtained. Vinyl 12 α-hydroxymethylabiet-7,8-enoate has been prepared from 12 α-hydroxymethylabiet-7,8-enoic acid by vinyl interchange with vinyl acetate and has been homopolymerized, copolymerized with vinyl chloride, vinyl acetate, butadiene, and acrylonitrile, and terpolymerized with styrene and acrylonitrile. Polymers thus obtained have been characterized.     

Hydrogen-bonded self-assemblies in a polychlorotriphenylmethyl radical derivative substituted with six meta-carboxylic acid groups

The synthesis, self assembly and magnetic properties of a polychlorotriphenylmethyl radical, substituted with six meta-carboxylic groups, are reported showing that radical-radical hydrogen bonds in the solid state yield to very weak intermolecular ferromagnetic interactions.     

A novel urocanic acid derivative from skin tissue extracts; (E)-3-[1-(1,1-dimethyl-3-oxobutyl)imidazol-4-yl]propenoic acid

A novel derivative of urocanic acid ( 1 ) had been isolated from acetone extracts of rabbit skin tissue. It proved to be (E)-3-[1-(1,1-dimethyl-3-oxobutyl)imidazol-4-yl]propenoic acid ( 3c ), potentially a much better ultraviolet screening agent than urocanic acid. Sterical effect of dimethyl groups in the side chain adjacent to the imidazole ring of 3c on its solubility is also discussed.     

Boryl‐substituted 1‐silacyclobutenes. Formation and molecular structure

The 1,2‐hydroboration of the chloro(hexyn‐1‐yl)‐ ( 1a ) and chloro(phenylethyn‐1‐yl)diphenylsilanes ( 1b ) with 9‐borabicyclo[3.3.1]nonane afforded selectively the alkenylsilanes 2a, b , in which the boryl and the silyl groups are linked to the same olefinic carbon atom. In case of 2a , treatment with phenylethynyl lithium gave a mixture of the alkyn‐1‐ylborate 3a and the alkenyl(phenylethynyl)diphenylsilanes 4a . In the case of 2b , only the alkyn‐1‐ylsilane 4b was identified as an intermediate. Both 4a, b slowly rearranged by intramolecular 1,1‐vinylboration into the silacyclobutenes 5a, b . The intermediates were characterized by ¹H, ¹¹B, ¹³C and ²⁹Si NMR spectroscopy in solution, and the molecular structure of the 1‐silacyclobutene 5a was determined by X‐ray analysis. The gas phase geometries of model molecules corresponding to 5a were optimized by MO calculations using DFT methods [B3LYP/6‐311 + G(d,p) level of theory], found to be in reasonable agreement with the results of the crystal structure determination, and NMR parameters were calculated at the same level of theory. Copyright © 2006 John Wiley & Sons, Ltd.     

Products derived from oxidations of 3,4-dimethyl-1-phenylphosphole-1-oxide: A 3-phenyl-5,6-dimethyl-2,3-oxaphosphabicyclo[2.2.2]octene-3-oxide derivative as a precursor of phenyl metaphosphonic anhydride

Oxidation of 3,4-dimethyl-1-phenylphosphole with peracids or peroxides gives a relatively stable P-oxide, which can be used in Diels-Alder reactions to give derivatives with the 7-phosphanorbornene framework. Oxygen insertion into a C–P bond of this framework occurs smoothly with m- chloroperbenzoic acid (MCPBA) providing derivatives of the 2,3-oxaphosphabicyclo [2.2.2] octene ring system. The phosphole can be converted to this system in a one-pot synthesis by reaction with excess MCPBA in the presence of N-phenylmaleimide as dienophile. The phosphole oxide undergoes mono-epoxidation with MCPBA. Thermal or photochemical fragmentation of the 2,3-oxaphosphabicyclo [2.2.2] ocetene is a useful source of the 3-coordinate species Ph–PO₂, a meta-anhydride of phenylphosphonic acid. This species was trapped successfully with a variety of alcohols.     

Attempted synthesis of a substituted [2.2.2]propellane derivative from triptycene derivatives

Bromotriptycene derivatives substituted at the bridgehead were subjected to varying reaction conditions in the attempt to obtain a substituted [2.2.2]propellane. The desired cyclization was not effected. The bromine atoms were replaced by hydrogens.     

Synthesis of a cisplatin derivative from lithocholic acid

A new steroidal-platinum(II) hybrid compound was synthesized using a simple and efficient methodology. The synthesis was performed by a convergent approach with cross metathesis (CM) as a key step. An olefin derived from lithocholic acid and a vinyl substituted ethylenediamine derived from l-serine were used as chiral building blocks, which were combined in the CM step. The most important advantage of this method was the utilization of l-serine as a cheap, stereoisomerically pure substrate. A steroid with a diamino system in the side chain was subjected to reaction with potassium tetrachloroplatinate to obtain the target platinum(II) complex. Attempts to synthesize similar diamine systems using the asymmetric Strecker reaction were unsuccessful.     

A substituted 1-azaadamantane derivative by “one pot” cyclisation of monocyclic monoterpenoids

Cyclisation of monocyclic amines $\text{via}$ iminium intermediates provides a facile synthesis of a substituted 1-azaadamantane derivative.     

Lactam and acid amide acetals 68. 1-Cyanomethyl-2-pyrrolidone diethylacetal in the synthesis of 7,8-trimethylenepurine derivatives

1-Cyanomethyl-2-cyaniminopyrrolidine was synthesized by the reaction of 1-cyanomethyl-2-pyrrolidone diethylacetal with cyanamide. The product undergoes Thorpe—Ziegler cyclization under the influence of sodium ethoxide to give 2-amino-3-cyano-5,6-dihydro-7H-pyrrolo[1,2-a]imidazole, from which 4-amino derivatives of pyrrolo[2,1-f]purine were synthesized.See [1] for Communication 67.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 754–758, June, 1991.     

Synthesis of 1, 10-dec anedicarboxylic acid from cyclododecatriene-1,5,9

Summary A simple synthesis of 1,10-decanedicarboxylic acid has been developed, starting from cyclododecatriene-1,5,9.     

New routes to 1-deoxy-(3,4-dihydro-7,8-dimethyl-2,4-dioxopyrimido[4,5-b]-quinolin-10(2H)yl)-D-ribitols (5-deazariboflavins)

The acid-catalyzed reaction of 6-(N-D-ribityl-3,4-xylidino)uracil ( 1 ) with trimethyl ortho-formate yields a bis(methoxymethylene) derivative ( 2 ), which is readily deprotected to give 5-deazariboflavin ( 3 ). Correspondingly, 5-methyl-5-deazariboflavin ( 6 ) is produced by cyclization of the tetraacetate of 1 with acetyl chloride in the presence of stannic chloride followed by deacetylation.     

Pyrroloindoles. 10. Synthesis of some substituted pyrroloindoles and tetrahydropyrrolocarbazoles

The formation of linear four-ring pyrrolocarbazole systems is observed in the indolization of cyclohexanone 1-acetyl-5-indolinyl- and 1-acetyl-6-indolinyl-hydrazones, whereas the formation of mixtures of linear and angular pyrroloindoles is observed in the cyclization of the corresponding acetophenone hydrazones.See [1, 2] for communications 8 and 9.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 470–474, April, 1984.