Expeditious synthesis

In a related work, the same authors present an expeditious synthesis of functionalized dihydronaphtofurans starting from dihydronaphtodioxines and stabilized phosphonium ylides [39]. 

Transformation of chiral nitrones into enantiomer enriched a-chiral N -hydroxylamines and their derivatives, has been successfully employed in the enantioselective synthesis of (+ )-(R)- and (—)-(S)-zileuton (216). An expeditious synthesis of thymine polyoxin C (347), based on the stereocontrolled addition of 2-lithiofuran (a masked carboxylate group) to the A-benzyl nitrone derived from methyl 2,3-O-isopropylidene-dialdo-D-ribofuranoside, is described (Scheme 2.151) (194). 

Fujino, A., Asano, M., Yamaguchi, H., Shirasaka, N., Sakoda, A., Ikunaka, M., Obata, R., Nishiyama, S. and Sugai, T., Bacillus subtilis epoxide hydrolase-catalyzed preparation of enan-tiopure 2-methylpropane-l,2,3-triol monobenzyl ether and its application to expeditious synthesis of (R)-hicalutamide. Tetrahedron Lett., 2007, 48, 979. 

The reaction can be also applied to azoles (e.g., imidazoles, pyrazoles, triazoles, tetrazole) as the N -nucleophile for the hydroaminations of cyclic olefins. In this case, the presence of methyl benzoate sensitizes the photoisomerization of the double bond to form a highly strained ( )-cycloalkene. Protonation of this intermediate by triflic acid (TfOH, 20mol%) and addition of the azole nucleophile completes the reaction sequence [41]. As an example, the expeditious synthesis of l-(l-methylcy-clohexyl)- H-imidazole (27) in 72% yield is shown in Scheme 3.17 [41]. 

Protti, S., Fagnoni, M. and Albini, A. (2005) Expeditious synthesis of bioactive allylphenol constituents of the genus Piper through a metal-free photoallylation... 

A most expeditious synthesis of triquinacene was described by Deslongchamps and his co-workers in 1973 (Scheme 58).3S°) This approach comprised degradation of Thiele s acid (363) to diketone 364 and photolysis of this intermediate to give keto aldehyde 365. Aldolization of365 led to construction of the tricyclic nucleus sequential hydride reduction, mesylation, and elimination of this intermediate over alumina efficiently provided 356. 

Siddiqui IR, Siddique SA, Srivastava V et al (2008) A novel anthranilic acid based multi-component strategy for expeditious synthesis of 4(3/7)-quinazolinone A-nucleosides. Arkivoc (xii) 277-285... 

Kumar D, Kumar NK, Sundaree S et al (2010) An expeditious synthesis and anticancer activity of novel 4-(30-indolyl)oxazoles. Eur J Med Chem 45 1244—1249... 

Li Z, Xing Y et al (2006) Microwave-assisted expeditious synthesis of novel carbazole-based... 

Truscott BJ, Klein R, Kaye PT (2010) Expeditious synthesis of NO-substituted N-mesitylimidazolium salts as NHC precursors. Tetrahedron Lett 51 5041-5043... 

Controlled hydrogenolysis of a methoxy substituent has been used to advantage in an expeditious synthesis of the tetrahydronaphthoic acid (122), an important starting material for the total synthesis of gib-berellins, i.e. regioselective metallation of 1,6-dimethoxynaphthalene (120) at C-7 followed by carboxylation to afford (121) and then reduction furnished (122) in 71% overall yield (Scheme 21). ... 

Baxter, E W, Reitz, A B, Expeditious synthesis of azasugars by the double reductive amination of dicarbonyl sugars, J. Org. Chem., 59, 3175-3185, 1994. 

VauzeiUes, B, Cravo, D, Mallet, J M, Sinay, P, An expeditious synthesis of a C-disaccharide using a temporary ketal connection, Synlett, 522-524, 1993. 

BaIczewski, F., Mikolajczyk, M. An Expeditious Synthesis of ( )-Desepoxy, 5-didehydromethylenomycin A Methyl Ester. Org. Lett. 2000,... 

The synthesis of the triazole nucleus has gained great importance in organic synthesis. A solvent-free and expeditious synthesis of l-aryl-4-methyl-l,2,4-triazolo[4,3-a]quinoxalines was developed that utilizes a mixing of a relatively benign non-metallic oxidant, iodobenzene diacetate (PhI(OAc)2, Scheme 8.2). ... 

Balczewski, P., and Mikolajczyk, M.. An expeditious synthesis of ( )-desepoxy-4,5-didehydrometh-ylenomycin A methyl ester, Org. Lett.. 2. 1153, 2000. 

Muthukrishnan M, Basavanag UMV, Puranik VG (2009) The first ionic liquid-promoted Kabbe condensation reaction for an expeditious synthesis of privileged bis-spirochromanone scaffolds. Tetrahedron Lett 50 2643-2648... 

The lignan styraxin (215) shows interesting antitumoural activity, and an expeditious synthesis of this molecule has now been... 

A three-component expeditious synthesis of 3,6-diaryl-5-mercaptoperhydro-2-thioxo-l,3-thiazin-5-ones from 2-methyl-2-phenyl-l,3-oxathiolan-5-one, an aromatic aldehyde, and an N-aryldithiocarbamic acid has recently appeared [194]. The synthesis is diastereoselective and involves tandem Knoevenagel, Michael, and ring transformation reactions occurring under solvent-free MW irradiation conditions in a single pot (Scheme 8.81). 

Lithiated a-amino nitriles derived from an enantiomerically pure secondary amine have been used to achieve the asymmetric synthesis of trfl 5-dibenzylbutyrolactones (scheme 10) [58]. Enantiomeric excesses of greater than 96% were obtained after removing the chiral auxiliary. When aromatic aldehydes were used as electrophiles the benzylic alcohols were obtained as a mixture of the two epimers with a diastereomeric excess of 60-75%. Addition of a chiral sulfoxide, prepared using a modified Sharpless oxidation, to butenolide has also been utilised as part of an expeditious synthesis of podophyllotoxin (scheme 11) [59]. 

Expeditious Synthesis of 1-Aryi-4-methyi-1,2,4-triazoio[4,3-a]quinoxalines... 

F. Manea, C. Bindoli, S. Polizzi, L. Lay, and P. Scrimin, Expeditious synthesis of water-soluble, monolayer-proteeted gold nanoparticles of controlled size and monolayer composition, Langmuir, 24 (2008) 4120-4124. 

Varma, R.S., Saini, R.K., Kumar, D. 1998. An expeditious synthesis of flavones on montmoril-lonite K 10 clay with microwaves. Journal of Chemical Research, Synopses 348-349. 

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