BICYCLO 3 3 l NONAN-9-ONE

Bicyclo[3.3 l]nonan-9-one, (2,4-dinitrophenyl)hydrazone (8,9) (—) Monochloroborane diethyletherate Borane, chloro-, compound with ethyl ether (8), Borane, chloro-, compound with 1,1 -oxybis[ethane] (1 1) (9) (36594-41-9). 

Target selection and synthetic strategy in solution Compound 3.25 contains a condensed lactone and a selenium-based substituent appropriate transformations of the two groups should give access to diverse tricyclic compounds. A more radical decoration of the nucleus (3.28, Fig. 3.17) could reasonably be conceived to fuUy exploit the bicyclo[3.3. l]nonan-9-one nucleus. Literature search found arelated approach (22) where a similar, less congested tricyclic nucleus 3.29 was prepared by selenium-... 

Snatzke has extended the useful analysis of the effect of 3-substituents upon the circular dichroism of adamantanones and substituted bicyclo[3,3,l]-nonan-9-ones. With earlier studies the effect of a wide range of substituents is now established, and the failure of the octant rule to account for the observed results is clear, but a satisfactory general analysis of substituent effects is still awaited. 

Reaction of the diazomethyl ketone (578) with activated copper oxide under irradi-ative conditions gave the phenylcyclopropyl ketone (579) which, on treatment with lithium in liquid ammonia, suffered unusual C-1—C-8 bond cleavage to give the bicyclo[3,3,l]nonan-2-one derivative (580). The ease of this bond cleavage is rationalized as a result of ct-jc overlap between the C-1—C-8 a-bond and the carbonyl-n-orbital. Further results on the BFj.OEtj-catalysed cyclization of cyclo-oct-4-enylidene derivatives in benzene solution to 9-siibstituted-l-phenylbicyclo[3,3,l]-nonanes have been reported. The trifluoroacetic-acid-catalysed ring closure of frans-3-(p-chlorobenzyl)-l,3,5,5-tetramethylcyclohexanol at 60°C affords a new... 

On the basis of the results described in 2.2.2.3., namely, the easy intramolecular ketal formation of 131 to 133, the question arose whether endo-6-hydroxy-9-oxa-bicyclo[3.3.1]nonan-2-one 214) might analogously be converted to the corresponding l-methoxy-2,7-dioxa-twistane 219). The experiments, even under drastic acidic conditions in methanol (5.5N HCl in CH3OH, 2 days at 80°), showed that no ring closure 214 219 occurred. Introduction of an endo-methyl group at C(7), however,... 

A soln. of 2,2-bis(chloromethyl)acetophenone in acetonitrile added dropwise during 0.5 hr. to N-cyclohex-l-enylpyrrolidine, triethylamine, and acetonitrile, stirring continued 1 hr., the solvent removed, first at atmospheric pressure and finally in vacuo, water added to the resulting immonium salt, and stirred 12 hrs. at room temp. -> 3-benzoylbicyclo[3,3.1]nonan-9-one. Y 81%. F. e. s. H. Stetter, K. D. Ramsch, and K. Elfert, A. 1974, 1322 bicyclo[4.n.l]enones cf. W. C. Still, Synthesis 1976, 453 ring closure with 3-chlor-2-enamines cf. Synth. Meth. 31, 838. 

For bicyclo[3,3,l]nonane derivatives which are unsubstituted at positions 3 and 7, it has been shown in several cases that chair-chair conformations are preferred, although the cyclohexane rings are distinctly flattened with valence-angle increases (cc. 4°) beyond ideal tetrahedral values. However, derivatives with bulky endo substituents at positions 3 or 7 may adopt boat-chair conformations. Thus for 9-benzoyl-3a-bromo-9-azabicyclo[3,3,l]-nonan-2-one (74) and for the 2-hydroxy-analogue, it has been argued... 

Graindorge and co-workers" reported the synthesis of 2,5,7,9-tetranitro-2,5,7,9-tetraaza-bicyclo[4.3.0]nonane-8-one (113) (K-56, TNABN) from the nitration of 2,5,7,9-tetraazabi-cyclo[4.3.0]nonane-8-one dihydrochloride (112) with dinitrogen pentoxide in absolute nitric acid, the latter obtained from the condensation of urea with l,4-diformyl-2,3-dihydroxy-piperazine (111) in hydrochloric acid. Treatment of (112) with nitronium tetrafluoroborate in nitromethane results in the nitration of the piperazine ring nitrogens only and the isolation of (114) in 86 % yield (Table 5.2). 

Manzamenone J (66) had the same composition as manzamenone D (61) with a conjugated dienone (Xmax 317 nm) functionality. Analysis of several types of 2D NMR spectra of 66 led to a bicyclo[4.3.0]nonane ring system involving a l(6),2-dien-7-one chromophore. The stereochemistry of the vicinal methine protons on C-8 and C-9 were suggested to be anti from the NOESY spectrum of 66 showing substantial correlations from H-8 to H2-26 and H2-27. The stereochemistry of C-5 position relative to C-8 and C-9 portion remained unassigned. 

Ethereal methyllithium from methyl chloride added slowly under N2 with Dry Ice-acetone cooling via the double-ended needle technique (s. H. C. Brown et al., Organic syntheses via boranes, Wiley, 1975, p. 210) to a mixture of B-ethyl-9-borabicyclo[3.3.1]nonane and dry pentane, stirred 10 min. at -78°, allowed to come to room temp., stirred 1.5 hrs., water-cooled, acetyl chloride added drop-wise from a syringe, and stirred ca. 2 hrs. -> c/>y-bicyclo[3.3.0]oct-l-ylethylmethyl-borane (Y 97%) treated with alkaline HgOg in tetrahydrofuran cw-bicyclo-[3.3.0]octan-l-ol (Y 95%). - The above rearrangement by a variety of reducible compds. (in the above case acetyl chloride, which is converted into ethyl acetate) furnishes many compds. containing the d5 -bicyclo[3.3.0]oct-l-yl moiety whidi have previously been difficult to prepare. F. e. s. G. W. Kramer and H. C. Brown, Am. Soc. 98, 1964 (1976) one-pot procedure s. J. Org. Chem. 42, 2832 (1977). 

Nearly all examples of epoxidation of alkylidenecyclobutanes involve 3-chloroperoxybenzoic acid.15 58-70 This is because the conditions are mild, the workup is easy and few byproducts are formed. Generally, dichloromethane or chloroform is used as solvent. Solid sodium hydrogen carbonate is occasionally added to avoid acid-catalyzed rearrangement of the spiro compound. For example, 6-isopropylidene-l,4,4-trimethylbicyclo[3.2.0]heptan-3-one reacted with 3-chloroperoxybenzoic acid and sodium hydrogen carbonate to give 2,2,3, 3, 6-pentamethyl-spiro[3-oxabicyclo[4.2.0]octane-8,2 -oxirane]-4-one (4) in quantitative yield. However, without the use of sodium hydrogen carbonate, substantial amounts of 2,2,6,9,9-pentamethyl-3-oxa-bicyclo[4.3.0]nonane-4,8-dione (5) and 2,2,6,8,8-pentamethyl-3-oxabicyclo[4.3.0]nonane-4,9-dione (6) were also formed.15-64... 

The excision of the keto bridge present in tricyclo[5.3.1.1 ]dodecan-l 1-one taken from the work of Cha et al. on synthetic studies of taxol deserves special mention. Highly functionalized derivatives of bicyclo]5.3.1]undecane are obtained using the DIB/I2 system (Eq. 11) [38]. The fragmentation of a related derivative of oxabicyclo[3.3.1]nonan-9-one is used by the same authors as a key step in the synthesis of cK-2,8-disubstituted oxocanes (Eq. 12) [39]. 

In acetic acid or methanol containing a catalytic amount of sulphuric acid, ds,ds-cyclonona-2,8-dienone cyclizes to give mixtures of bicyclo[4,3,0]non-6-en-8-one and either endo- and exo-7-methoxy-cis-bicyclo[4,3,0]nonan-8-one or endo- and exo-1-acetoxy-ds-bicyclo[4,3,0]nonan-8-one 2% of 8-methoxy-ds-cyclonon-2-en-l-one was also isolated from the reaction in methanol. These cyclizations were found to be characteristic of the 9-membered cyclic dienone, analogous 7-, 8-, and 12-membered... 

Bromomethyl)-4,7-dimethoxyfuro[2,3-rf]pyridazine Spiro [cyclopentane-1,3 -bicyclo [4.1.0]heptane] (lR,3/ ,5S)-c 6 o-l,3-Dimethyl-2,9-dioxabicyclo[3.3.1]nonane Spiro [5.7]trideca-1,4-dien-3-one 1 -Benzoyl-2-phenylaziridine... 

A number of studies of a-elimination have employed 9,9-dibromobicyclo[6,l,0]-nonyl derivatives and one has led to optically active cyclonona-2,3-dienone. Loozen and his group have found that whereas endo-a ky atior of the 9,9-dibromo-bicyclo[6,l,0]-nonanes and -nona-2,4,6-triene can be effected, compounds (398) and (399) afford allenes under the same reaction conditions. This has been ascribed to bishomoaromatic interaction favouring facile disrotatory cleavage of the carbenoid as depicted by (400). Under different conditions, Baird and Reese have found that the A -isomer of (398), the 3,5-diene, and (401) yield allenes and not carbene re-... 

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