1 -Phosphabicyclo octane 1 -oxide

Ozoe et al.76 have determined the Kd values for complexes of ot- and fl-cyclo-dextrin with a variety of 4-substituted bicyclic phosphates (4-substituted 2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane 1-oxides, 1), which are highly toxic convulsants. 

Ethyl-2,6,7-trioxa-l -phosphabicyclo [2.2.2] octane 1 -Oxide C06-A002... 

Isopropyl-2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane 1-Oxide C06-A003... 

One example performed in this laboratory is the analysis of toxicity exerted by bicyclic phosphate esters 26). 2,6,7-Trioxa-l-phosphabicyclo[2.2.2]octane-l-oxides (IS) with suitable 4-substituents (R) are highly toxic to mammals 27). The 4-Et derivative... 

Phosphabicyclo-[2.2.1]heptane and -[2.2.2]octane 1-oxides can be prepared by the reaction of branched tribromides with triethyl phosphite by an Arbusov reaction, followed by a Grignard reaction in the presence of Mg in THF when the carbon-phosphorus rings are closed (equation (11)). When the JH and 13CNMR data were studied certain very large... 

Regioisomeric 1,2-dihydrophosphinine 1-oxides 21A, 21B, and 24 undergo the Diels-Alder cyclization with dimethyl acetylenedicarboxylate (DMAD) to give 2-phosphabicyclo [2.2.2] octane derivatives 22A, 22B, and 25 (Schemes 7 and 8). The 1,2-dihydrophosphinine 1-oxides 26 react with phenylmaleimide to give the corresponding tricyclic heterocycles 27 (four isomers) (Scheme 9). 

Substitution of the phosphinate ester group by dimethylamine via the chloride, and thionation of the P=0 group of the 2-phosphabicyclo[2.2.2]octane P-oxide derivatives 28 with diphosphorus pentasulfide affords the corresponding amide 29 and P-sulfide 30 (Scheme 10). The thionation is also achieved with Lawesson s reagent [7,8]. Thermolysis of 28 proceeds a retro Diels-Alder reaction to give 31. 

Scheme 10 Reactions of 2-phosphabicyclo[2.2.2] octane P-oxide derivatives 28 to give 29-31...

The electron impact induced fragmentation and rearrangements of 1-ethylphosphorinane 1-oxide, 1-phosphabicyclo[2.2.1]-heptane 1-oxide (13), and 1-phosphabicyclo[2.2.2)octane 1-oxide (14) have been investigated (G.L. Kenyon, D.H. Eargle, Jr., and C.W. Koch, J. org. Chem., 1976, 2417), and a study has been... 

Binding Characteristics. For ligand-receptor binding assays, we used an EDTA/Tris-citrate (1 mM, pH 7.4)-dialyzed mitochondrial fraction of housefly heads, the so-called 2 fraction, which was prepared by a modification of Squires s method (4). The final pellet was frozen at -25°C and then suspended in 50 mM Tris-citrate buffer (pH 7.4 at 3°C) for assays. 4-w-Propyl[2,3-3h]-2,6,7-trioxa-l-phosphabicyclo[2.2.2]— octane 1-oxide ([ HjPr-BP, 41 Ci/mmol) was used as a ligand for the reason described above. Radioreceptor assays were performed by filtration techniques with glass fiber filters. Specific [ HjPr-BP binding was taken as that displaced by excess unlabeled Pr-BP(10 yM). 

GABA, yaminobutyric acid BPE, bicyclic phosphorus ester DHP, a-dihydropicrotoxinin TBPS, 4-t-butyl-2,6,7-trioxa-l-phosphabicyclo-[2.2.2]octane 1-sulfide Pr-BP, 4-n-propyl-2,6,7-trioxa-l-phospha-bicyclo[2.2.2]octane 1-oxide BP, bicyclic phosphate pb, piperonyl butoxide EDTA, ethylenediaminetetraacetic acid disodium salt BH, bicuculline methiodide... 

The base-catalysed methanolysis of 4-methyl-2,6,7-trioxa-l-phosphabicyclo[2.2.2]-octane 1-oxide and 1-sulphide (41)(X = O or S) (Scheme 5) initially yields trans forms of... 

Phosphole oxides also participate in a cycloaddition reaction with oxyallyl cations <75T53>, a process that gives rise to novel phosphatropolone structures. Preformed 1,2,5-triphenylphosphole oxide gave a derivative of the 8-phosphabicyclo(3.2.1]octan-6-ene-3-one ring system ((157), 91%). The oxyallyl cation (156) was prepared from a,a -dibromodibenzylketone and Nal in acetonitrile (Scheme 31). 

Caged bicyclic phosphate IVG and IVH could be conveniently synthesized by the condensation of 4-(hydroxymethyl)-2,6,7 -trioxa-1 -phosphabicyclo[2.2.2]octane 1-oxide M21 or 4-(hydroxymethyl)-2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane 1-sulfide M22 and substituted phenoxyacetyl chlorides M5 or substituted phen-oxypropionyl chlorides M20 in the presence of triethylamine as a base (Scheme 9.28). 

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