2-Naphthalenone derivatives

Bicyclic 3a//-cyclopentene[8 annulcnc-l,4-(5//,9a//)-dioncs undergo three types of acid-induced transannular reactions (1) Michael addition (5-exo-trig or 6-exo-trig) leading to the tetracyclic diones, (2) 3 + 2-cycloaddition followed by a novel sequential skeletal rearrangement to 2-naphthalenone derivatives, (3) ipso-Friedel-Crafts alkylation accompanied by the rearomatization and the loss of water (Scheme 25). The factors that control the reaction mode of these transannular cyclizations are discussed... 

Ramamurthy et al. have examined enantioselective and diastereoselective ODPM rearrangements of cyclohexadienone and naphthalenone derivatives within MY zeolites, where M is an alkali ion [38, 39]. For example, in Scheme 4.27, in NaY in the presence of several chiral inductors such as ephedrine, pseudoephedrine, and camphorquinone-3-oxime, an enantioselective ODPM rearrangement of 65 and 66 took place to afford 68 in 30% ee yield. In the frame of the chiral auxiliary approach, the compound 67 linked to (S)-ephedrine was irradiated within NaY to give 68 in moderate diastereoselective excess (de) (59%). Interestingly, the reaction media of KY, RbY, and CsY reverse the diastereoselectivities. The cation-dependent diastereo-meric switch has been discussed with respect to the N- or O-functional group in 67 [39]. Recently, Arumugan reported that the irradiation of naphthalenones 65 linked chiral auxiliaries (R3 = COO(—)-Ment or (S)-NHCH(Me)Ph) in Li+ or Na + Nafion resulted in chiral products ( 14% de) [40],... 

In fact, the reaction proceeded as expected [23]. Thus, by heating the l-[o-(l-alkynyl)phenyl]cyclopropanol complexes 36-Co2(CO)6 in refluxing 2-propanol, 2,3-dihydro-1-naphthalenone derivatives 37 are obtained as a mixture of (Aland (Z)-isomers in moderate yield accompanied by a substantial amount of an ethyl ketone derivative formed by ring opening of the cyclopropanol moiety. Furthermore, when an analogous naphthyl derivative 38 was employed, the reaction proceeded cleanly and the 2,3-dihydrophenanthren-l-one derivative 39 was obtained in 83 % yield (Scheme 17). The obvious difference in reactivity between phenyl and naphthyl derivatives is probably due to the presence of hydrogen at the peri position of the latter. To avoid steric repulsion between the alkyne-Co2(CO)6 moiety and this hydrogen, the molecule adopts a conforma-... 

The intramolecular cycloaddition of the enone derivative (78) affords the adducts (79) in yields of around 58%. The advantage of this compound for synthetic purposes is that the alcohol group is functionalized by a novel protecting group. The adducts (79) can be converted into derivatives such as (80). Four intramolecular cycloaddition products (82) and (83) are formed on irradiation of the naphthalenone derivative (81)." ° Changes in the regiochemistry are observed when the irradiations are carried out on silica surfaces. 

Angular alkylations of fused-ring ketones are an important step in syntheses of terpenoids, steroids and related natural products. The steric course of these alkylations has therefore been the subject of several systematic investigations and has been reviewedl 3 71. Alkylation of the lithium enolate 38 (R = H) derived from octahydro-1 (2//)-naphthalenone (1 -decalone) primarily yields the civ-fused octahydro-8a-methyl-l(2F/)-naphthalenone (39, R = H)35,62,79. Due to steric reasons, the lithium enolate 38 (R = CH3), with an angular methyl group, provides the irans-fused product 39 (R = CH3). 

Quinol Derivatives. Feichtmayr and Scheibe (61,62) noted that photodissociation occurs for a large number of substituted quinols in carbon tetrachloride solution both at room temperature and at low temperature in glasses. The reversible formation of naphthoxy radicals from tetrachloro-l(4H)naphthalenone is represented as follows ... 

In contrast to o-phenylenediamines, l,8,naphthylenediamine and most of its derivatives react with 2,6-di-tert-buty 1-1,4-benzoquinone to give perimidinespirocy-clohexadienone 11 (Scheme 5).4,6-8 The reaction occurs readily under noncatalytic conditions when refluxing propanol or toluene solutions of the components. By contrast, catalysis of the reaction with strong proton acids (e.g., /Hoi ucncsul Ionic acid) is necessary for the preparation of 2,3-dihydro-2-spiro[4(4//)-2-fert-butyl-l-naphthalenone pcrimidine 4 when 2,6-di- fcrt-buty 1-1,4-benzoquinonc is replaced in this reaction by 2-fert-butyl- 1,4-naphthoquinone. 9... 

Starting from ( + )-8a-cyano-octahydro-2(l/f)-naphthalenone oxime, the corresponding (2/ ,4a/ ,8a.V)-2-chloro-2-nitmso derivative was prepared and employed in the cycloaddition with (2 , 4 )-2,4-hexadiene. The dihydro-1,2-oxazine 1 was obtained in good yield, but with only 39% ee. The configuration at C-6 was established as S, by correlation with known compounds40. 

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