Wang alcohol

Scheme 17 shows a synthesis of variably substituted dihydropyridazinones starting from y-keto adds 60, which were esterified with Wang alcohol resin to give 61. Initial attempts at sequential formation of hydrazones by reacting the ketone moiety with hydrazines and subsequent cyclization of the solid-phase-bound hydrazone did not work satisfactorily. Therefore, the authors developed a one-pot procedure in which the sohd-phase-bound y-keto acid 61 was reacted with an excess of substituted hydrazines in THF at elevated temperature. They isolated a range of dihydropyridazinones with R = Me, Ph and = H, alkyl, 4-MeOC6H4. 2-Acetyl-benzoic acid was a further template of a y-keto add which was reacted successfully giving benzo-fused derivatives [30]. 

Rapid loading of cross-linked PS Wang resin (4-(benzyloxy)benzyl alcohol PS) with a selection of /3-ketoesters was shown to reach completion within 1-10 min if microwave irradiation at 170 °C was employed. The conventional thermal method for acetoacetylation of hydroxymethyl-functionalized polystyrene resins takes several hours therefore, microwave heating allowed for... 

Volkow ND, Wang GJ, Begleiter H, et al Regional brain metabolic response to lorazepam in subjects at risk for alcoholism. Alcohol Clin Exp Res 19 510-316, 1995... 

Wang N, B Szostek, RC Buck, PW Folsom, LM Sulecki, V Capka, MR Berti, JT Gannon (2005) Fluorotel-omer alcohol biodegradation—direct evidence that perfluorinated carbon chains breakdown. Environ Sci Technol 39 7516-7628. 

Solid alkaline membrane fuel cells (SAMECs) can be a good alternative to PEMFCs. The activation of the oxidation of alcohols and reduction of oxygen occurring in fuel cells is easier in alkaline media than in acid media [Wang et al., 2003 Yang, 2004]. Therefore, less Pt or even non-noble metals can be used owing to the improved electrode kinetics. Eor example, Ag/C catalytic powder can be used as an efficient cathode material [Demarconnay et al., 2004 Lamy et al., 2006]. It has also... 

Wang used method D to fashion a key intermediate for the synthesis of rishirilide B (Fig. 4.20).21 The 2,4-bis-OBoc-3-methyl-benzyl alcohol (31) undergoes the addition of two equivalents of corresponding Grignard reagent to afford phenol 32 in 75% yield (Fig. 4.20). This material was subsequently elaborated by Mejorado in three steps (61% yield) to the corresponding 2,5-chiral cyclohexadienone 33, which was ultimately transformed into ( + )-rishirilide B (34).22... 

Wang SS. p-Alkoxybenzyl alcohol resin and p-alkoxybenzyloxycarbonylhy-drazide resin for solid-phase synthesis of protected peptide fragments. J Am Chem Soc 1973 95 1328-1333. 

Veeramachaneni, S., L. M. Ausman, S. W. Choi, R. M. Russell, andX. D. Wang. 2008. High dose lycopene supplementation increases hepatic CYP2E1 protein and inflammation in alcohol-fed rats. J Nutr (submitted). 

There are also some rare domino sequences where two anionic and two radical reactions are combined (Scheme 2.152) [347]. According to a report of the Wang group, thionyl chloride is able to promote a succession of reactions by an initial formation of a chlorosulfite 2-673 of the tertiary alcohol 2-672, followed by an SN-type reaction to produce the chloroallene 2-674. A Schmittel cyclization reaction [348] then generates... 

An example of solid-phase microwave synthesis where the use of open-vessel technology is essential is shown in Scheme 4.10. The transesterification of /3-keto esters with a supported alcohol (Wang resin) is carried out in 1,2-dichlorobenzene (DCB) as a solvent under controlled microwave heating conditions [22], The temperature is kept constant at 170 °C, ca. 10 degrees below the boiling point of the solvent, thereby allowing safe processing in the microwave cavity. In order to achieve full conversion to the desired resin-bound /3-keto ester, it is essential that the methanol formed can be removed from the equilibrium [22]. 

Wang, Y., and Davis, B. H. 1999. Fischer-Tropsch synthesis Conversion of alcohols over iron oxide and iron carbide catalysts. Applied Catalysis A General 180 277-85. 

Wang, Y. et al., Influence of chronic dietary ethanol on cytokine production by murine splenocytes and thymocytes, Alcohol Clin. Exp. Res., 18, 64, 1994. 

In the same year, Wang and Stack (211) reported the first truely catalytic system. They discovered that Complexes E and F shown in Fig. 28 can be oxidized by 1 equiv of tris(4-bromophenyl)aminiumhexachloroantimonate, (TPA)SbCl6, at -0.7 V Fc+/Fc to the corresponding (phenoxyl)copper(II) species, which in turn were shown to stoichiometrically convert 1 equiv of benzyl alcohol to benzaldehyde. In the presence of 20 equiv of (TPA)SbCl6 and base, Complex E displays catalytic behavior (-10 turnovers). 

The nucleophilic attack on an acceptor-substituted allene can also take place at the acceptor itself, especially in the case of carbonyl groups of aldehydes, ketones or esters. Allenic esters are reduced to the corresponding primary alcohols by means of diisobutylaluminum hydride [18] and the synthesis of a vinylallene (allenene) by Peterson olefination of an allenyl ketone has also been reported [172]. The nucleophilic attack of allenylboranes 189 on butadienals 188 was investigated intensively by Wang and co-workers (Scheme 7.31) [184, 203, 248, 249]. The stereochemistry of the obtained secondary alcohol 190 depends on the substitution pattern. Fortunately, the synthesis of the desired Z-configured hepta-l,2,4-trien-6-ynes 191 is possible both by syn-elimination with the help of potassium hydride and by anti-elimination induced by sulfuric acid. Analogous allylboranes instead of the allenes 189 can be reacted also with the aldehydes 188 [250]. 

J. Liang, Y. Huang, L. Zhang, Y. Wang, Y. Ma, T. Guo, et al., Molecular-level dispersion of graphene into poly(vinyl alcohol) and effective reinforcement of their nanocomposites, Advanced Functional Materials, 19 (2009) 2297-2302. 

Liu W, Zhang X, Xu G, Bradford PD, Wang X, Zhao H, et al. Producing superior composites by winding carbon nanotubes onto a mandrel under a poly(vinyl alcohol) spray. Carbon. 2011 Nov 49(14) 4786-91. 

Suli Wang, Direct Alcohol Fuel Cell Laboratory, Dalian Institute of Chemical Physics, P.O. Box 110, Dalian 116023, China... 

Chen, S.-T., Chen, S.-Y. and Wang, K.-T., Kinetically controlled peptide bond formation in anhydrous alcohol catalyzed by the industrial protease alcalase. J. Org. Chem., 1992, 57, 6960. 

Figure 10.1 Recovery of collectorless (dashed line) and butyl xanthate induced flotation (solid line) of chalcopyrite as a function of pulp potential. Solid line-butyl xanthate 2.9 x lO mol/L, dashed line-collectorless flotation Butyl ether alcohol 7.5 mg/L (Wang, 1992)...

Wang JC, Himichs AL, Stock H, et al. (2004) Evidence of common and specific genetic effects association of the muscarinic acetylchohne receptor M2 (CHRM2) gene with alcohol dependence and major depressive syndrome. Hum Mol Genet. 13, 1903-1911. 

---