Oxidation of spiroketones with DDQ - synthesis of tropone derivatives and DDHQ diesters
作者:Tirumalai R. Kasturi、Palle V.P. Pragnacharyulu、Gouravaram M. Reddy、Srirangam K. Jayaram、Sheo B. Singh
DOI:10.1016/s0040-4020(01)88302-2
日期:1992.1
derivatives 4a–f and DDHQ esters 5a–f (- isomer 6a–f, - isomer 7a–f). While the aryl substituted spirokeone 17a gave a 2:1 mixture of 19a and the corresponding - isomer, the aryl substituted spiroketones 17b–d gave exclusively - isomers 19b–d. Heating acid chloride of acid 9c with DDHQ resulted in compounds 4a and 7a, thus confirming the structuresassigned. Mechanism of formation of these compounds
用干苯中的DDQ氧化螺酮3a-f,得到托克酮衍生物4a-f和DDHQ酯5a-f(-异构体6a-f,-异构体7a-f)。而芳基取代spirokeone 17A给予了2:1混合物19A相应的和-异构体,所述芳基取代的spiroketones 17B-d仅仅得到-异构体19B-d 。用DDHQ加热酸9c的酰氯得到化合物4a和7a,从而确认分配的结构。这些化合物的形成机理已经合理化。对化合物7d的2D 1 H- 1 H COSY,1 H- 13 C COSY,HMBC和2D NOESY的详细研究导致1 H和13 C NMR信号及其溶液构象的完全分配。
Oxidation of bis(2-hydroxy-1-naphthyl)methane and similar bisnaphthols with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Structure and synthesis of novel products
作者:Tirumalai R. Kasturi、Betageri Rajasekhar、Gonibella J. Raju、Gowravaram Madhusudhan Reddy、Ramamoorthy Sivaramakrishnan、Narayanan Ramasubbu、Kailasam Venkatesan
DOI:10.1039/p19840002375
日期:——
the structures were finally confirmed by an X-raycrystalstructure analysis of (12a). Hydrogenation of compounds (12a) and (13a) has been shown to give the dihydroxy compound (14) via C–C bond cleavage. An alternative synthesis of the dispironaphthalenones (12a) and (13a) was achieved by oxidation of the dihydroxy compound (14), prepared by an independent method. The generality of the oxidation of
Reaction of spironaphthalenones with hydroxylamine: Part I. A reinvestigation of the mechanism
作者:Tirumalai R. Kasturi、Srirangam K. Jayaram、Palle V.P. Pragnacharyulu、Jitendra A. Sattigeri、Gowravaram M. Reddy、Kaipenchery A. Kumar
DOI:10.1016/s0040-4020(01)80511-1
日期:1993.1
Spironaphthalenones 1b–g on reaction with hydroxylamine hydrochloride gave the expected pyrrolotropones 2b–g. Furanotropone 6, postulated as an intermediate in the formation of pyrrolotropones, remained unchanged on reaction with hydroxylamine hydrochloride in ethanol. Reaction of unsymmetrical spironaphthalenones 1h–o with NH2OH.HCl gave the rearranged pyrrolotropones 2h–o.
DDQ oxidation of bisnaphthols - structures of novel products
作者:Tirumalai R. Kasturi、Srirangam K. Jayaram、Jitendra A. Sattigeri、Palle V.P. Pragnacharyulu、Tayur N. Guru Row、Renuka K、Kailasam Venkatesan、Noor Shahina Begum、Netaji Munirathinam
DOI:10.1016/s0040-4020(01)87985-0
日期:1993.8
Oxidation of bisnaphthols (1a-c) with DDQ resulted in the formation of 10a-a″, 10b-b″, 14a-c and 19a-c in addition to earlier reported products. Structures were assigned on the basis of detailed spectral analyses(1H, 13C, 1H1H HOMOCOSY and FUCOUP). Structures 10b, and 14c and 19a were further confirmed by single crystal X-ray analyses. The formation of these compounds has been explained by a suitable
Cu(<scp>ii</scp>)-catalyzed domino construction of spironaphthalenones by dearomatization of β-naphthols and using <i>N</i>,<i>N</i>-dimethylaminoethanol as a C1 synthon
作者:Meiqi Geng、Jinqiang Kuang、Maozhong Miao、Yongmin Ma
DOI:10.1039/d3ob00296a
日期:——
A Cu(ii)-catalyzed tandem construction of synthetically valuable spiro compounds from 2-naphthols and N,N-dimethylethanolamine (DMEA) in air is reported.