Hydrindans

Only the heteroannular diene 523 is formed by treatment of both a- and, 3-allylic carbonates 522 and 524 in a hydrindan. system with a Pd catalyst. No homoannular diene is formed. 

A third variation of this strategy has been appHed to an enantioselective total synthesis of cortisone. From an appropriately functionalized, scalemic hydrindan that possessed an 11-oxo-group and a masked corticoid side-chain, (+)-cortisol was produced in an 11-step total synthesis (213). 

The driving force for ring expansion of 17-hydroxy-20-keto steroids probably comes from relief of strain accompanying conversion of trans-fused hydrindanes to tra/75-fused decalins. The greater susceptibility to rearrangement of 17/ -hydroxy-20-ketones as compared to the 17a-hydroxy-20-... 

It is of note that hypoglycemic activity is maintained even when the aromatic ring is fused onto a carbocyclic ring. Chlor-sulfonation of hydrindan gives chloride, 206. Reaction of the sulfonamide (207) obtained from that intermediate with cyclohexyl isocyanate leads to glyhexamide (208). ... 

A potenti illy useful approach to the marine ilkaloid papiiairune based on INOC strategy is proposed as shown m Scheme 8.21. In fact, a Rruir-hydrindane intermediate has been synthe-SLzed in racemic form using a model sequence ofreacdons involving an itnle oxide cycloaddidon as a key step fEq. 8.69. ... 

The extensive study of Craig and coworkers [116] on the intramolecular Diels-Alder reactions of E- and Z-sulphonyl-substituted deca-, undeca- and dodecatrienes 120 (Figure 2.13) has opened a short route to trans- and cis-bridgehead hydrindanes and decalines and has given new insights into the role of dienophile substitution and geometry in determining the stereochemical outcome of these intramolecular cycloadditions. 

Winterfeldt E. Enantiomerically Pure Cyclopentadienes Chem. Rev. 199393 827 843 Keywords synthesis of steroid cyclopentadienes, hydrindan dienes and their kinetic resolution... 

It is clear then that more than one mechanism is operative for glycol fission. In the case of c -cyclopentanediols and camphanediols a cyclic ester is a necessary intermediate. For tra/js-decalin-9,10-diol a non-cyclic mechanism must operate which cannot function for cholestane-3/ ,6j8,7a-triol and is inefficient for /rans-camphanediols. It is pertinent that while the fission of glycols capable of forming cyclic esters proceeds several hundred times faster in benzene than in acetic acid, the reactions of trans-decalin-9,10-diol and tra/ij-hydrindane-l,6-diol are 4-5-fold slower in benzene . ... 

Mehta, G. Reddy, D.S. (2000) A Formal Synthesis of Reserpine Hydrindane Approach to the Woodward s Ring-E Precursor. Journal of the Chemical Society Perkin Transactions J, 1399-1404. 

Xb was utilized in the elaboration of the hydrindan XIII and subsequently compound XIV. We expected that Xa could be converted to XIII in the same manner as was in the Sih synthesis. This was confirmed in practice (Scheme II). Oxidation of 569 mg (2.68 mmol) of Xa with pyridinium chlorochromate in methylene chloride furnished 532 mg (94%) of enone Ila (7,21). Treatment of 130 mg of Xa witlj a slight excess of Jones reagent (3,22) afforded 126 mg (98%) of Ila. Allylic brominatlon of Ila with a 20% excess of N-bromosuccinimide (NBS) in refluxing carbon tetrachloride provided Xlla in 98% yield. 

As an example, reactions of2-734a and 2-734b with 4 equiv. of Sml2 led to the an-nulated cyclopentanes 2-741a and 2-741b in good to excellent yields. However, the process is less suitable for the preparation of hydrindanes 2-741c. 

Trauner and coworkers released a report on a unified approach to isopropyl containing frans-hydrindane sesterterpenes via a common intermediate [38]. Their effort provided compounds that lend themselves to the substitution patterns embedded in retigeranic acids A (1) and B (2) as well as oxygenated precursors providing access to other sesterterpenes such as nitidasin (6), astellatol (3), and YW3699 (89). 

After the known intermediate 79 (contaminated with ca. 6 % < /.v isomer) [39] was prepared from Hajos-Parrish ketone [40] 78, the tert-butyl ether was cleaved (quant.) and the ketone protected as the acetal (96 %). The secondary alcohol was oxidized by pyridinium chlorochromate (PCC) to provide ketone 80 in good yield (71 %) and after fractional crystallization afforded material absent of any m-hydrindane (Scheme 10.6). [NOTE All compounds shown in Schemes 10.6 and 10.7 are shown in the ent-configuration, as published]. The oxidation of protected hydrindane 80 under Saegusa-Ito conditions [41, 42] gave enone 81 (82 %), confirmed by X-ray crystallography. 

Recently, the silane-mediated reductive cyclization of activated alkynes with tethered ketones using Stryker s reagent as a catalyst was reported.112,90b Alkynyl ketone substrate 84a was treated with a catalytic amount of Stryker s reagent in the presence of polymethylhydrosiloxane (PMHS) to afford the cA-fused hydrindane 84b as a single diastereomer. This method is applicable to both five- and six-membered ring formation, but often suffers from competitive over-reduction of the reaction products (Scheme 59). 

A similar result was reported by Vandewalle 15°-151>. Irradiation of 1,2-bis(tn-methylsiloxy)cyclobutene and compounds (441) afforded compounds (442), which were reduced with LiAlH4 to give the endo alcohol (443). Treatment of the alcohol (443) with methanol for 24 hours would bring about silylether cleavage as well as unexpected direct oxidation of (443) to the cis-hydrindanes (444) in 50-70 % yield (Table 18)130). 

In contrast, when /f-D-mannopyranosylamine reacts with thiophosgene, only the cis bicyclic thionocarbamate is formed and the transient isothiocyanate cannot be detected (Scheme 4). The different behaviour of the cis and trans hydrindane-type systems can be explained by the strain in the ring fusion for a trans species. 

The larger (Z,Z)-l,5-cyclononadiene (169) reacts141 stereoselectively with PhSeCl in AcOH to give the substituted hydrindan 170 (equation 138). In consideration of the anti addition mode of selenenyl reagents to double bonds, the transannular reactions of 169 have been rationalized on the basis of the two reaction intermediates, 171 or 172, which are liable to place the PhSe- and AcO- groups in a cis- 1,4-relationship and trans to the bridgehead hydrogen (equation 139). The preferential formation of 170 has thus been attributed to the fact that the pathway via 172 should involve a boat transition state. 

The thallium trinitrate-mediated ring contraction of frani-decal-2-ones has opened up a new route to the hydrindane system, and fluorinative ring contraction of cyclic alkenes to afford difluorocycloalkanes has been induced by iodotoluene difluoride and EtsN-HF. A possible mechanism is shown in Scheme 78. The double bond of the cyclohexene ring is attacked by iodotoluene difluoride activated by HF from the axial direction, followed by the addition of a fluoride ion from the trans direction. Reductive elimination of iodotoluene from the resulting adduct, ring contraction and the addition of the fluoride ion to the carbocation stabilized by fluorine then take place to give the ring-contracted difluorinated product. 

Synonyms AI3-02275 BRN 1904376 2,3-Dihydroindene 2,3-Dihydro-l/f-indene EINECS 207-814-7 Hydrindane Hydrindene Hydrindonaphthene Indane NSC 5292 UN 1993. 

Hydracrylic acid p-lactone, see p-Propiolactone Hydralin, see Cyclohexanol Hydrazine-benzene, see Phenylhydrazine Hydrazinobenzene, see Phenylhydrazine Hydrazobenzene, see 1,2-Diphenylhydrazine l,T-Hydrazobenzene, see 1,2-Diphenylhydrazine Hydrazodibenzene, see 1.2-Diphenylhydrazine Hydrazomethane, see Methylhydrazine Hydrindane, see Indan... 

The fusion of rings of different sizes reduces symmetry in the structures instead of the rather unusual situation with the decalins, where there are only two configurational isomers, the hydrindanes exist in the... 

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