2.6- dimethyl-7-oxabicyclo- -heptane

Moreover, reaction of 6,6-dimethylbicyclo[3.1, l]heptan-2-one with an aqueous suspension of magnesium monoperoxyphthalate at 80 °C gave 7,7-dimethyl-2-oxabicyclo[4.1.1]octan-3-one in only 0.5 % yield,24... 

Furthermore, when the enantiomerically pure diol 5 is treated with /V-iodosuccinimide in acetonitrile in the dark at 20 C for 16 hours, smooth cyclization gives (17 ,2 S, 4 S,)-l-iodomethyl-3,3-dimethyl-7-oxabicyclo[2.2.1]heptan-2-ol (6) in 76% yield. Recrystallization affords an optically pure sample109. 

Hydrolysis of ( —)-methyl (15,3S)-(2,2-dimethyl-3-tosyloxycyclobutyl)acetate, obtained by a stereocontrolled route from (-f )-a-pinene, with zinc(II) acetate in aqueous dimethoxyethane at 80 °C leads to optically active 5-lactone ( —)-(lS,65)-2,2-dimethyl-3-oxabicyclo[4.1.0]heptan-4-one (1) in 62% yield.In addition to this cyclopropane derivative, a carboxylic acid was isolated which on treatment with diazomethane gave (-f )-methyl (5,5-dimethyl-2-tetrahydrofuryl)acetate (2). 

In order to relate these observations to the extensive information available on the mechanistic and stereochemical consequences of solvolytic tosyloxycydobutane rearrangements, the hydrolysis was performed in aqueous 1,2-dimethoxyethane at 80°C. The optically active (5-lactone ( —)-(15 ,65)-2,2-dimethyl-3-oxabicyclo[4.1.0]heptan-4-one (21) was isolated in 60% yield as the only neutral component. By acidification of the remaining aqueous phase, extraction, and methylation with diazomethane, (-h )-methyl 5,5-dimethyltetrahydrofurylacetate (22) was obtained. ... 

On the basis of the 1,3-dipolar cycloaddition of 5-membered ring carbonyl ylides, syntheses of oxabicyclo[2.2.1]heptan-2-one ring systems were successfully accompUshed. For example, the reactions of the cyclopropyl-substituted five-membered ring carbonyl ylide 48 derived from the a-diazo ketone 47 with different dipolarophiles have been investigated [78-80]. The compound 47 undergoes cycloaddition in the presence of Rh2(OAc)4 with dimethyl maleate, dimethyl fumarate, cyclopentenone, 1,1-dimethoxyethylene and bi-cyclopropylidene furnishing the expected cycloadducts 49-53, respectively... 

Oxa-3-azaindene. See Benzoxazole Oxaban -A. See Dimethyl oxazolidine Oxaban -E. See 7-Ethyl bicyclooxazolidine 7-Oxabicyclo [4.1.0] heptane. See Cyclohexene... 

Cantharidin (2,3-dimethyl-7-oxabicyclo[2,2,1 ]heptane-2,3-dicarboxylic anhydride) as an antitumor agent A retrospective review 13CMD159. Cyclometallated iridium(III) complex with 2,2 -biquinoline N-donor hgand as a c-myc G-quadruplex stabiHzer and down-regulator of c-myc oncogene expression 13CMD576. 

Dimethoxy-2,2-dimethyl-2//-1 -benzopyran, D-70365 1 -(Dimethoxymethyl)-2,3,5,6-tetrakis(methylene)- 7-oxabicyclo[2.2.1]heptane, D-60399 Flossonol, F-60014... 

Two dimethyl substituted derivatives have been studied that is endo,exo- and exo,exo-2,6-dimethyl-7-oxabicyclo[2.2.1]heptane. Only the former monomer yielded a polymer. The exo,exo-isomer (6) will not polymerize since the conformational forms of the repeat unit are unfavourable. In the two chair conformations two substituents will be in axial positions and in one form a l,3 diaxial interaction will exist between the methyl groups ... 

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