Inden-l-one

K)-6,7-dichIor<)-2,3-dihydro-5-methox -2- 3-oxobutyl)-2-propyl-1 -inden-l-one yield 95% 80% ee... 

Dihydro-1-vinylnaphthalene (67) as well as 3,4-dihydro-2-vinylnaphtha-lene (68) are more reactive than the corresponding aromatic dienes. Therefore they may also undergo cycloaddition reactions with low reactive dienophiles, thus showing a wider range of applications in organic synthesis. The cycloadditions of dienes 67 and 68 and of the 6-methoxy-2,4-dihydro-1-vinylnaphthalene 69 have been used extensively in the synthesis of steroids, heterocyclic compounds and polycyclic aromatic compounds. Some of the reactions of dienes 67-69 are summarized in Schemes 2.24, 2.25 and 2.26. In order to synthesize indeno[c]phenanthrenones, the cycloaddition of diene 67 with 3-bromoindan-l-one, which is a precursor of inden-l-one, was studied. Bromoindanone was prepared by treating commercially available indanone with NBS [64]. 

Since dihydroarylethenes are more reactive than the corresponding fully aromatic compounds, their use in the cycloaddition reactions is preferred in order to carry out the reactions under mild conditions with higher yields. Some reactions of 3,4-dihydro-1-vinylnaphthalene (103) [33], 3,4-dihydro-2-vinyl-naphthalene (104) [34], and l,2-dihydro-4-vinylphenanthrene (105) [35] with 4-acetoxy-2-cyclopentenone (98) and 2-inden-l-one (106) are summarized in Schemes 5.11-5.13. 

CN 2,3-dihydro-5,6-dimethoxy-2-[[l-(phenylniethyl)-4-piperidinyl]methyl]-l/7-inden-l-one hydrochloride... 

As a part of a broad study dealing with the development of synthetic methods for polycyclic aromatic compounds, Minuti and colleagues77 prepared some [5]phenacenes and fluorenoanthracenes via Diels-Alder reactions between dienes such as 59 and several activated dienophiles. Oxidation of the primary adducts with DDQ afforded the desired polycyclic aromatic compounds. Equation 21 shows the reaction between 3,4-dihydro-1-vinylanthracene (59) and in situ generated 2-inden-l-one (60) which afforded a 3 1 mixture of regioisomers 61 and 62 with 51% overall yield. 

Catalytic asymmetric methylation of 6,7-dichloro-5-methoxy-2-phenyl-l-indanone with methyl chloride in 50% sodium hydroxide/toluene using M-(p-trifluoro-methylbenzyDcinchoninium bromide as chiral phase transfer catalyst produces (S)-(+)-6,7-dichloro-5-methoxy-2-methyl-2--phenyl-l-indanone in 94% ee and 95% yield. Under similar conditions, via an asymmetric modification of the Robinson annulation enqploying 1,3-dichloro-2-butene (Wichterle reagent) as a methyl vinyl ketone surrogate, 6,7 dichloro-5-methoxy 2-propyl-l-indanone is alkylated to (S)-(+)-6,7-dichloro-2-(3-chloro-2-butenyl)-2,3 dihydroxy-5-methoxy-2-propyl-l-inden-l-one in 92% ee and 99% yield. Kinetic and mechanistic studies provide evidence for an intermediate dimeric catalyst species and subsequent formation of a tight ion pair between catalyst and substrate. 

Probably the first unambiguous structural analysis of a FOZ by single-crystal XRD was that of 302, derived from a substituted indene-l-one, by ozonization, as shown in equation 99 . ... 

Fig.4 Separation of rac-ferroceno[2,3a]inden-l-ones on a poly(tetrakis(e do/exo-6-0-norborn-2-ene-5-ylmethoxymethylsilyl)-/3-CD)-grafted column. Conditions T=21.5°C, flow 0.5 mL/min, acetonitrUe-MeOH-acetic acid-triethylamine (90 10 0.15 0.45), UV-detection...

Methoxy-2a-methyl-2,2a,7,7a-tetrahydro-l//-cyclobut a inden-l-one Typical Procedure 113... 

Dihydro-5,6-dimethyoxy-2-[[l-phenylmethyl)-4-piperidinyl] methyl]lH-inden-l-one. 

Dimethoxy-2-[[l-(phenylmethyl)4-piperidinyl-methyl]-2,3-dihydro-lH-inden-l-one. 

Preparation of 3-bromo-6-methoxy-2-(4-methoxyphenyl)-lH-inden-l-one and 3-bromo-5-methoxy-2-(4-methoxyphenyl)-lH-inden-l-one... 

A mixture consisting of 3-bromo-6-methoxy-2-(4-methoxyphenyl)-lH-inden-l-one (0.4345 mmol), sodium ethanethiolate (1.09 mmol) and 0.5 ml triethylamine dissolved in 3 ml DMF was heated 24 hours at 80°C and then cooled. The mixture was then poured into water and extracted with EtOAc. Extracts were washed with brine, dried, purified by flash chromatography using 10% EtOAc/petroleum ether, and the product isolated in 89% yield as a dark red solid, mp = 88-90°C. 

Table 1 Selected 2-(4-hydroxyphenyl)-lH-inden-l-one derivatives and their corresponding melting points and mass spectral characterization data...

Table 2 ERa and ER(3 binding affinities for selected 2-(4-hydroxyphenyl)-lH-inden-l-one derivatives. Although derivatives exhibited a range of activity, the higher receptor affinity selectivity profile of ER(3 over ERa indicates their usefulness in treating disorders modulated by ER(3...

These nitroso nitro compounds were converted to amines and diamines, probably as mixtures of isomers. For example, the 2,3-dihydro-l /f-indene-1,2-diamine hydrochloride prepared via 2,3-dihydro-2-nitro-l/f-inden-l-one oxime has mp 280 °C (dec)92, while the authentic cis-iso-mer93 has mp 304-308 °C. Furthermore, 2,3-dihydro-l-methyl-l//-inden-2-amine obtained by direct hydrogenation of the l-methyl-17/-indene derivative92 has the same melting point (201 — 202 "C) as the 1 1 mixture of the cis- and trans-isomers94. 

The anodic methoxylation of aromatic compounds such as naphthalene [41], anthracene [42], alkylbenzenes [31,43], phenols [44-46], anisoles [33,47-54] and other alkoxyben-zenes [53], methoxynaphthalenes [33], methoxyanthracenes [50,54], inden-l-ones [55], / a/r/-substituted anilides [56] and heterocyclic compounds, such as furans [57], thiophenes [58], and pyrroles [59], has received considerable attention. 

Additions similar to those reported for methoxysubstituted aromatic compounds are observed also for vinyl ethers, as in Eq. (24) [60,61], inden-l-one [55], furans [57], thiophenes [58], and pyrroles [59]. 

To a solution of 5-methoxy-l/f-inden-l-one (1.63 g, 10.2 mmol), benzene (20 mL) and CHClj (20 mL) was added, over 2 h via syringe pump, a solution of diphenyldiazomethane (2.22 g, 11.5 mmol) in benzene (15 mL). A gentle reflux was maintained during the addition. After the addition was complete the solution was refluxed for 3 h and then stirred at rt for 18 h. Neutral workup yielded 3.20 g of a purple oil, which was chromatographed on a silica gel column (4x35 cm ) fraction 1 1 L of 2% EtjO in hexane, diphenyl-... 

Addition of diazomethane to 2-substituted 3-alkylsulfanyl-17/-inden-l-ones 8 afforded dihydropyrazoles 9 which rearranged to mixtures of 2-substituted 4-alkylsulfanyl-l-naphthols 11 and 3-alkylsulfanylmethyl-l//-inden-l-ones 12 on pyrolysis. 

The 1-naphthol 11 was accompanied by the corresponding inden-l-one 12 in each case. 

The cyclopropane-containing intermediates were isolated in several cases. Furthermore, it was found that l//-inden-l-ones 13 could be directly ring expanded to 1-naphthols 15 by treatment with lithium methylsulfinylmethanide, without isolation of any of the intermediates. Addition of the inden-l-one 13 to methylsulfinylmethanide, prepared from dimethyl sulfoxide and butyl-lithium, gave after 24 hours, a mixture of the 1-naphthol 15 and the j8-hydroxy sulfoxide 16. ... 

Multi-ring heteroaromatic compounds containing furan and thiophene rings have been prepared by pressured cycloaddition of 2-vinylbenzo[ ]furan (40a) and 2-vinylbenzo[Z)]thiophene (40b) with 3-nitro-2-cyclohexen-l-one (41) and 2-inden-l-one (42), respectively, generated in situ. ... 

The cycloadditions of 2-inden-l-one (42) generated in situ are regioselective and cycloadducts 46 are converted into pentacyclic heterohelicenes 47. 

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