Bicydo hept

Bicydo 2.2.1 hept-2-en endo-1-Methoxyinethyl-5-nitro- E16d, 252 ([4 + 2]-Cycloaddition) Carbamidsaure N-Benzyloxy- ... 

Decan 2,4,7.9-Tetraoxo- EI9a, 736 (Dehydrodimerisierung) 2,7-Dioxa-bicydo 3.2.0 hept-3-en 6-Butyloxycarbonyl- E14a/I, 456 (Furan + OHC—COOR)... 

Bicydo 2.2.1]hept-2-en 2-Dimethyl-amino-5-(l -ethoxy-ethoxy)-E15/1, 619 (Keton + Aminobo-ran)... 

Bicydo 4.1.0 hepta-2,4-dien-<7-spiro-l)-indan-< 3-spiro-7> -bicy clo 4.1.0 hept-2,4-diene... 

In addition, the Baeyer-Villiger oxidation of racemic bicydo[3.2.0]-hept-2-en-6-one with E. coli pQR209 gives about 50% of nearly enantiomerically pure (lR,5S)-3-oxabicyclo octenone as shown in Fig. 6 this regioisomer cannot be made selectively by chemical Baeyer-Villiger oxidation. In both cases, a yield of product on substrate of 85 to 90% has been obtained. Applying a ketone feed rate which keeps the reactant concentration below the inhibitory concentration was essential. 

Cyclopropane derivatives are the major products of photoelimination of nitrogen from 1-pyrazolines. Conversion of the fused pyrazoline (10) into the cyclopropane (11) was achieved in this way in 85% yield by irradiation in the presence of acetophenone and constitutes a valuable step in a synthesis of a diquinane alcohol. The short-lived triplet 1,3-cyclopentadiyl biradical, generated by benzophenone-sensitised irradiation of diazabicyclo-(2.2.1]hept-2-ene, has been trapped as a Jbis-alkoxyamine by a nitroxide. The diazabicycloheptenes (12) gave in a similar fashion the bicydo[2.1.0]pentanes (13) on triplet-sensitised photolysis, whereas laser/liquid jet excitation of the same compounds gave in addition the cyclopentenes (14), derived by 1,2-hydrogen shift evidence for a two-photon process is described. The results of a time-resolved spectroscopic study of the photodecomposition of 2,3-diazabicyclo[2.2.l]hept-2-ene in the vapour phase have also been reported.Photolysis of 2,3-diaza-5-methylenebicyclo[2.2.l]hept-2-ene affords the semi-localised... 

In the case of bicydo[3.2.0]hept-2-en-6-one, each one of the substrate enantiomers reacts with a different and divergent regioselectivity for the oxygen atom insertion. This result is noteworthy since it describes for the first time such an almost perfect... 

The biotransformation of bicydo[3.2.0]hept-2-en-6-one using whole cell suspensions of the fungus Cylindrocarpon destructans gave not only different ratios of both lactones depending on the degree of conversion, but also no enantioselectivity was... 

Further studies also been performed on the bicydo[3.2.0]heptan-6-one series of compounds1124, 125]. These results are summarised in Fig. 16.5-35. Oxidation of this ketone with Pseudomonas NCIMB 9872 gave the (IS, 5 R)-lactone of low optical purity (23% ee) with only small amounts (5%) of the isomeric lactone, whereas its oxidation with an Acinetobacter sp. gave these lactones in a 9 1 ratio and a modest yield, a result quite different from the one described previously. However, oxidation of 7-mdo-methylbicydo[3.2.0]hept-2-en-6-one using either Pseudomonas sp. or Acinetobacter sp. produced optically pure (ee > 96 %) of both lactones in equal quantities... 

Endo 3a1415,617,7a-Hexahydro-4l7-methano-2-lndene-i-one (2).1 A solution ol octacarbonyMcobalt (1.0 g, 3 mmol) and bicydo [2 2.11 hept-2-ene 1 (3.0 g. 32 mmol) in isooctane (100 ml) was stirred first with acetylene and then under a mixture ot 1.1 of acetylene and carbon monoxyde at 60-70°C until gas absorption ceased (total 1550 ml). The mixture was concentrated and the residue chromatographed on neutral alumina. Petroleum ether PhH (1 1) eluted acetylene hexacarbonyl dicobalt 70 mg, PhH CHCI3 (1.1) eluted a yellow oil which alter rfisfiltation afforded 3 54 g of 2 (74%), bp 101-102°C (15 mm) Colorless crystals (rom pentane, mp32°C. 

Russell has reported the preparation of bicyclo[3,2,0]hept-2-en-6,7-semidione (582). Reaction of the bicyclo[2,2,l]heptene acyloin (583) with potassium t-butoxide in DMSO gives (582). The rearrangement may occur via the enediol dianion, as the bicyclo[2,2,l]heptene semidione itself, generated by an alternative route, is stable. The methylated bicyclo[2,2,l]heptene acyloins (584a) and (584b) both yielded mixtures of the possible bicydo[3,2,0]heptene semidiones (585) and (586) on treatment with butoxide in DMSO. The rearrangement was shown to be reversible, since the same mixture of semidiones was formed from l-methylbicyclo[3,2,0]hept-2-en-6,7-acyloin (587). 

The capability of ROMP of polymerizing even more complex functional monomers was demonstrated by the fact that the cationic NHC precursor l,3-di(l-mesityl)-4- [(bicydo[2.2.1 ]hept-5-en-2-ylcarbonyl)oxy]methyl -4,5-dihydro-lH-imidazol-3-ium tetrafluoroborate can be polymerized with the Schrock initiator Mo(N-2,6-f-Pr2-C6H3) (CHCMe2Ph)(OCMe(CF3)2)2 at ambient temperature in CH2CI2. The observed theoretical DP of 7 was in excellent accordance with a DP of 7 1 found via end-group analysis using H-NMR. The polymerization system fulfilled at least the requirements of a class-V living polymerization system. 

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