Bicyclo nonane-4,9-dione

The 2,4-dien-l-one system (203) is unusually prone to nucleophilic addition, giving the 3a,5a-epoxyketone (204) in aqueous alkaline solution, or the bicyclo-[3,3,l]nonane-dione analogue (205) with acetone and an acidic catalyst. 

Acylation of the enamine (113) with a,/9-unsaturated acid chlorides has been shown (57) to give bicyclo(3.3.1)nonan-2,9-diones. Acryloyl ehloride on reaction with the enamine (113) and subsequent hydrolysis gave bicyelo-(3.3.1)nonan-2,9-dione (123). Mechanistic studies suggest that C alkylation by the olefin precedes acylation (87). 

An interesting variant of this reaction is the formation of 2-thiaadamantane-4,8-dione by hydrolysis of the reaction product of the bispyrrolidine enamine of bicyclo[3.3.1]nonane-2,6-dione with sulfur dichloride (106). 

Bicyclof 3.3.1 ]nonane-2,6-dione (10) A solution of 10 g of Meerwein s ester, 30 ml of glacial acetic acid, and 20 ml of 6 A hydrochloric acid is heated under reflux for 10 hours. The solution is then carefully distilled under aspirator pressure until all volatile materials (water and acetic acid) are removed. The solid residue is distilled at 129-131°/4 mm to afford the product. It may be recrystallized from benzene giving about 3 g of bicyclo-[3.3.1]nonane-2,6-dione, mp 138-140°. 

Non-8-en-4-olide, 3(R)-7(R)-epoxy-4(R)-8-dimethyl Lf 0.002NT349 Nonacosane-8-lO-dione Stigma Nonan-2-ol, 3-3-5-trimethyl-8-iso-propyl-4-9-dioxa-bicyclo-(3.3.1) Lf ... 

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... 

Bicyclo[5.2.0]nonane-l,7-diol was oxidized by potassium periodate in water at room temperature to yield cyclononane-1,4-dione (6). 56... 

Various attempts to hydrolyse 9-ethylenedioxybicyclo[3.3.1]nonane-3,7-dione under acid conditions resulted only in the formation of either 5-hydroxyindan-2-one (HCl/AcOH 14% yield) or a mixture of the indanone (13%) and 7,9-bis(ethylenedioxy)bicyclo[3.3.1]nonan-3-one (13% 10% aqueous HC1). 

Photochemically induced transannular ring closure of bicyclo[3-3.1 -nonane-3,7-dione to 3,7-noradamantane diol is illustrated in Eq. (38)12S). 

Similar a,a -annulations were achieved from reaction of oc,/ -unsaturated acid chlorides with cyclic ketone enamines which afforded bicyclo[3.3.1]nonane-2,9-diones41,60 65 or bicyclo[4.3.1]decanones66. In this reaction, 7V-acylation of the enamine 109 occurs as the first step giving 110, followed by a [3,3] sigmatropic rearrangement to a ketene intermediate (111). Ketene 111 subsequently cyclized via 112 to a bicyclic immonium salt (113) which after hydrolysis gave the corresponding dione 11463. If there is an axially oriented electrophilic substituent at C-4 of the enamine (for example, R = COPh) the enolate anion 115 may cyclize to an adamantane derivative 116 (equation 20). 

The reaction of a,)3 Unsaturated acid chlorides with enamines has become a useful method for the a,a -annulation of ketones " . Acyclic ketones are converted into aminocyclohexenones in good yield and hydrolysis gives the corresponding cyclohexa-1,3-dione " (Scheme 143). Application of the reaction to enamines of cyclohexanones gives bicyclo[3,3,l]nonane-2,9-diones . The yields are greatly affected by the experimental conditions used and, in the presence of triethylamine, the course of the reaction is changed completely and tetrahydrochromanones are usually the main or only product " (Scheme 144). 

A synthesis of tricyclo[3,3,3,0 ]undec-2(6)-ene (252), starting from bicyclo[3,2,2]-nonane-6,8-dione, has been described (252) is reactive and was characterized as its Diels-Alder adduct with diphenylisobenzofuran. In the absence of the diene, the production of (252) leads to the formation of the dimer (253), which is clearly the result of the ene addition of two molecules of the bridgehead olefin. 

Bicyclo[3.3.1]nonane-2,4-dione, B-70103 Bicyclo[2.2.2]oct-2-ene-1 -carboxylic acid,... 

Double ring closure. A mixture of bicyclo[3.3.1]nonane-3,7-dione, o-phenylene-diamine, and molecular sieve 3A refluxed 2 hrs. in benzene product. Y 81%. R. Yamagudii, K. H. Yang, and M. Kawanisi, Bull. Chem. Soc. Japan 46, 673 (1973). 

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