Pentacyclo decane

Pentacyclo-nonane (homocubane) V Pentacyclo-decane (bishomo-cubane) J... 

Marchand and co-workers ° synthesis of 5,5,9,9-tetranitropentacyclo[5.3.0.0 .0 °.0 ] decane (52) reqnired the dioxime of pentacyclo[5.3.0.0 .0 °.0 ]decane-5,9-dione (49) for the incorporation of the four nitro groups. Synthesis of the diketone precursor (48) was achieved in only five steps from cyclopentanone. Thus, acetal protection of cyclopentanone with ethylene glycol, followed by a-bromination, and dehydrobromination with sodium in methanol, yielded the reactive intermediate (45), which underwent a spontaneous Diels-Alder cycloaddition to give (46). Selective acetal deprotection of (46) was followed by a photo-initiated intramolecular cyclization and final acetal deprotection with aqueous mineral acid to give the diketone (48). Derivatization of the diketone (48) to the corresponding dioxime (49) was followed by conversion of the oxime groups to gem-dinitro functionality using standard literature procedures. 

Die Umsetzung von l-Methoxycarbonyl-3-nitro-10-oxo-pentacyclo[5.3.0.02 5.03,9.04,8]decan mit N-Brom-succinimid (NBS) in waBr. 1,4-Dioxan-Losung und anschlicBende Ozonolyse liefert 3,I0-Dinitro-l-metho-xycarbonyl-pentacyclo[5.3.0.O1. 0A,li decan (16%)2. 

Direct irradiation of the (CH)10 hydrocarbon triquinacene (26) in pentane solution gave five different (CH)10 isomers along with some naphthaline and azulene. The two major products were pentacyclo[4.4.0.02 4.03 i0.05,9]dec-7-ene (27), arising from an intramolecular [2 + 2] cycloaddition, and hexacyclo[4.4.0.02,4.03,10.05,8.07 9]decane ( barettane , 28), which is formed via a di-n-methane rearrangement (see Section l.A.2.2.) followed by an intramolecular [2 + 2] cycloaddition,50... 

Derivatives of homocubanecarboxylic acids are selectively available from bis(a-halo ketones) with the bishomocubane skeleton by protection of the carbonyl functions. Thus, 5-bromo-10,10-(ethylenedioxy)pentacyclo[5.3.0.02,6.03,9.05 8]decan-4-one and the corresponding 1,5-di-bromo derivative gave 9,9-(ethyIenedioxy)pentacyclo[4.3.0.02 5.03-8.04,7]nonane-4-carboxyIic acid (6a)61 and the 1-bromo derivative 6b,62 respectively, in good yields. 

In this manner. l,5-dibromo-10,10-(elhylenedioxy)pentacyclo[5.3.0.02-5.0349.04 8]decan-6-one was converted to 8-bromo-9,9-(ethylenedioxy)pentacyclo[4.3.0.02 5.03-8.04-7]nonane-4-car-boxylic acid (9) in 92 % yield. After conversion to the a-bromo ketone, a repeated ring contraction using 25% aqueous potassium hydroxide gave dimethyl cubanedicarboxylate 10 in 25% yield after methylation with diazomethane.64... 

Chlordecone [143-50-0] or decachloro-5-oxo-pentacyclo-[5.3.0.02,6,03,9,04,8]-decane (38) (mp 349°C dec) is the 2-keto analogue of mirex and is soluble in water to 4 g/L by hydration. The rat LD50s are 95,140 (oral) and >2000 (dermal) mg/kg. Chlordecone is a stomach poison used in baits for the control of cockroaches and ants and for the control of banana thrips. Because of bioaccumulation its registrations were canceled in the United States in... 

Pentacyclo 5.3.1.014.0J s.04 9Inn-decan E19b, 601 (Cyclisie-rung)... 

DODECACHLOROOCTAHYDRO-1.3.4-METHENO-1H-CYCLOBUTA(c,d)PENTALENE DODECA-CHLOROPENTACYCLODECANE DODECACHLORO-PENTACYCLO(3,2,2,o2.6 o3.9,o5.10)DECANE ENT 25,719 FERRIAMICIDE HEXACHLOROCYCLOPENTADI-ENEDIMER l,2,3,4,5,5-HEXACHLORO-l,3-CYCLO-PENTADIENE DIMER HRS 1276 NCI-C06428 PERCHLORODIHOMOCUBANE PERCHLOROPENTA-CYCLODECANE PERCHLOROPENTACYCLO-(5.2,1, o2. 5,o3.5,o5.8)DECANE... 

Isomerization. The l,l -bishomocubane derivative (1) is rearranged to (2), dimethyl c(j-pentacyclo[4.4.0.02,10.03,5.04 9]decane-7,8-dicarboxylate, in quantitative yield by stirring with an aqueous methanolic solution of silver nitrate.1 This transformation had been carried out unknowingly by French chemists2 by... 

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