Dioxabicyclo decane

Formation of the intermediate organomercury peroxide 56 was rationalised in terms of an allylic mercuration providing an unsaturated hydroperoxide 55 that can cyclise by the favoured 54) 5-exo mode (equation 42 X = 02CCF3). However, this was not the main reaction pathway and the yields (2.7% and 0.6% of 2,m-10-dibromo-8,9-dioxabicyclo[5.2.1]decanes 54 were an order of magnitude lower than those of the 2,6-dibromides 53 obtained from 1,4-cyclooctadiene. 

Double sequential ene-yne ring-closing metathesis on a series of chiral 3,4-bisallyloxybut-l-ynes using both Grubbs catalysts has been used to generate chiral dioxabicyclo[4.4.0]decanes (Scheme 48) <2003JOC7889>. 

I3C-NMR spectroscopic data of heteroanalogs of bicyclo[4.4.0]decane, collected prior to 1983, have been summarized25 77. Therefore, only a selection of subsequent studies is noted. H- and 13C-NMR spectra of diastereomeric substituted cis- and rraw-4-hydroxy-l-oxabicyclo[4.4.0]-decanes642, as well as H-NMR spectra of isomeric perhydrooxazolo[3,4-a]quinolines 3 and 3,3a,4,5-tetrahydro-1 //-oxazolo[3,4-a]quinolines 4, have been discussed 643. The 3H data of five diastereomeric 5-methyl-3-phenyl-2,4-dioxabicyclo[4.4.0]decanes have been reported644. 

In 1999 Uemuraetal. isolatedattenol A (100) and B (101) (Fig. 1.2.5), both marine natural products exhibiting a moderate cytotoxicity against P388 cells [57], from the Chinese Pinna attenuata. Since they are isomeric triols they differ only in the hydroxyl groups involved in the formation of the ketal functionality, so that this results in a l,6-dioxaspiro[4.5]decane and a 6,8-dioxabicyclo[3.2.1]octane unit as the main structural feature of attenol A and B, respectively. 

Chiral dioxabicyclic systems are selectively formed from 3,4-bisallyloxybut-1-yne derivatives under an ethylene atmosphere. A single RCM is performed when a RuCl2(PCy3)2(= CHPh) is employed, while the cascade RCM of dienyne is the major reaction with a second generation Grubbs catalyst (Scheme 5). In this case, the substitution of the allyloxy groups can selectively lead to dioxabicyclo[4.4.0]decane or to dioxabicyclo[5.3.0]decane [13]. 

Since treatment of 4-acetyl-3-methyl-6,6-diphenyl-l,2-dioxan-3-ol and l-hydroxy-4,4-diphenyl-2,3-dioxabicyclo[4.4.0]decan-7-one with a mixture of 1,1-diphenylethene and manganese(III) acetate did not afford any spirodiper-... 

Antimalarial testing was performed for the five synthesized 1-hydroxy-8-aza-2,3-dioxabicyclo[4.4.0]decane-6-carboxylates (R =Et, NEt2, cyclohexyl, or Ph R =Et R = R" = 4-CIC6H4 in Scheme 21). Unfortunately, the azadioxabicyclo[4.4.0]decane-6-carboxylates did not show any activity against Plasmodium falciparum, but a cytotoxicity toward EM3A [175]. However, it was found that both 4,4-bis(2-hydroperoxy-2,2-diphenylethyl)-l,2-diphenylpyrazolidine-3,5-dione (Scheme 24) and 4-benzyl-4-hydroperoxy-l,2-diphenylpyrazolidine-3,5-dione (Scheme 27) showed a weak antimalarial activity [162]. 

Abstract A large number of marine natural products with bicyclic and/or spirocyclic acetals have been found to date. These compounds are usually biologically active, however, synthetic studies are essential for the structure elucidation and biological application. For spirocyclic acetals in particular, it is necessary to design precursors and to control the process of dehydrative ring-closing acetal formation. Synthetic studies of four types of acetal compounds that represent recent examples are described didemniserinolipid B (6,8-dioxabicyclo[3.2.1]octane), attenols (6,8-dioxabicyclo[3.2.1]octane or l,6-dioxaspiro[4.5]decane), bistramides (l,7-dioxaspiro[5.5]undecane), and pinnatoxins (6,8-dioxabicyclo[3.2.1 ]octane and 1,7,9-trioxadispiro[5.1.5.2]pentadecane)... 

CliHiftOs, Methyl (1S,5S,6S,7R)-6-formyl-7-methyl-2,8-dioxabicyclo-[3.3.1]non-3-ene-4-carboxylate, 46B, 312 Cl1H1gOa, 3-Hydroxy-trans-bicyclo[4.4.0]decane-1,3-carbolactone,... 

H26O6 f 1Rf6S-4S,10S-Dihydroxy-3R-(2S-hydroxy-1S-methyl-propyl) 2,8-dioxabicyclo[4.4.0]decan-9S-yl-acetone, 45B, 339 15H2 eOe f 1S,6R-8R-(IS,3S-Dihydroxy-2S-methylbutyl)-5S-hydroxy-3,7-dioxabicyclo[4.3.0]nonan-4S-y1-acetone, 45B, 339 5H2sOiOf Euonyminol, 43B, 404... 

C7H13O3P, 1-Phospha-2,10-dioxabicyclo[4.4.0]decane 1-oxide, 44B, 604 C7H15BF4N3P, 7-Methyl-l,3,5-triaza-7-phosphonioadamantane tetra-fluoroborate, 44B, 605... 

A strain-free homologue of the nucleus in prostaglandin endoperoxides, namely 8,9-dioxabicyclo[5,2,l]decane can be conveniently prepared from cyclo-octa-1,4-diene (Scheme 22). ... 

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