5-Acetyl-2-tert.-butyl

Arylthio-acetyl)-tert.-butyl- E13/1, 814 (Cl O-OR) [4-(subst.-Benzoyl)-benzoyl)-tert.-butyl- E13/1, 823 (Cl -. O-OR) Bis-[l-alkoxycarbonyl-alkoxycarbo-nylj- E13/1, 922 (R0-CO-Cl + H2O2) Bis-[2-arylsulfonyl-ethyl]- E13/1, 319 (En + H202)... 

Di-O -acetyl- "-tert -butyl-2-deoxy-3-thio-D-aroZ)in -hexopyranose, D-375... 

Acetyl chloride, a-tert butyl-o-cyano- [Butyryl chloride, 2-cyano-3 3-dimethyl-], 55,38... 

Interesting developments in simple azetidine chemistry continue to be reported. The apparently general acetylative dealkylation of Af-tert-butyl-3-substituted azetidines 6 (R = Bu ) in the presence of boron trifluoride provides a two-step route to azabicyclobutane 7 from 6 (R = Bu, R = Cl). An aqueous solution of 7 reacts with ethyl chloroformate to give 8. Relatively unexplored 3-azetidinones 9 (R = Ac or NO2) are available from 3-acetoxya2Ktidine 6 (R = Ac, R = OAc) which is obtained by acetylative dealkyation of 6 (R = Bu , R = OAc) <96JOC5453>. 3-Substituted azetidines can be utilized in the synthesis of polyfunctional y- and S-aminophosphonic acid derivatives <95TL9201>. 

Attention has been given to possible adverse effects of incorporating tert-butyl methyl ether into antomobile fuels. tert-Butyl formate is an established product of photolysis, and it has been shown that photolysis in the presence of NO can produce the relatively stable tert-butoxyformyl peroxynitrate. This has a stability comparable to that of peroxy-acetyl nitrate, and may therefore increase the potential for disseminating NO (Kirchner et al. 1997). 

Silica sol-gel inunobihzed La(OTf)3 (Scheme 48.2B) previously used in the acylation of a series of alcohols and activated aromatic compounds using acetic anhydride as acylating agent, showed a poor activity compared with other various sihca sol-gel inunobihzed triflate derivatives (tert-butyl-dimethylsilyl-trifluoromethane-sulfonate (BDMST), or trifhc acid (HOTf)). Acylation at the aromatic ring occurred over the BDMST and HOTf catalysts, while the La(OTl)3 catalysts only led to O-acetylated products [22]. Such behavior is characteristic... 

A Lewis acid is also necessary for the acetylation of tetracarbonylferrate using N-acetylimidazole. In the absence of a Lewis acid, a Claisen-type condensation product was formed, which has been synthesized independently from 2 moles of A-acetylimidazole with sodium terf-butanolate in tert-butyl alcohol (55% yield) or with imidazole sodium in THF (95% yield) ... 

All reactants should be pure and anhydrous. The tert.-butyl alcohol should be dried over quicklime and the dimethylani-line redistilled. Reagent grade acetyl chloride should be employed. 

The preparation of enantiomerically pure chemicals is also the theme of the next group of four procedures. The biopolymer polyhydroxybutyric acid, which is now produced on an industrial scale, serves as the starting material for the large scale synthesis of (R)-3-HYDROXYBUTANOIC ACID and (R)-METHYL 3-HYDROXYBUTANOATE. Esters of (-)-camphanic acid are useful derivatives for resolving and determining the enantiomeric purity of primary and secondary alcohols. An optimized preparation of (-)-(1S,4R)-CAMPHANOYL CHLORIDE is provided. The preparation of enantiomerically pure a-hydroxyketones from ethyl lactate is illustrated in the synthesis of (3HS)-[(tert)-BUTYL-DIPHENYLSILYL)OXY]-2-BUTANONE. One use of this chiral a-hydroxyketone is provided in the synthesis of (2S,3S)-3-ACETYL-8-... 

Table 1 Anomeric alkylation of OH-1 of acetylated or unprotected sugars with tert-butyl bromoacetate...

Triazoles (386, R1 = COOMe) were treated with potassium tert-butylate in a mixture of f r/-butanol and benzene for 15-60 min to give (substituted amino)methoxycarbonylmethylenemalonates (387, R1 = COOMe) in 28-54% yields. In the case of the acetyl derivative (386, R = Ph, R1 = COMe), the reaction was carried out in chloroform in the presence of triethylamine at ambient temperature for 8 hr, to give (pheny-lamino)acetylmethylenemalonate (387, R = Ph, R = COMe) in 38% yield. (Phenylamino)acylmethylenemalonates (387, R = Ph,R = COMe, COPh) were also prepared in 62-74% yields when diazo derivatives (388, R1 = COMe, COPh) were heated in benzene for 4-24 hr (80T1821) (Scheme 34). 

Acetyl cyclohexanesulfonyl peroxide, 3033 Bis(3-carboxypropionyl) peroxide, 2990 Bis(2,4-dichlorobenzoyl) peroxide, 3623 Bis(2-hydroperoxy-2-butyl) peroxide, 3078 Bis(l-hydroperoxycyclohexyl) peroxide, 3553 O-O-tert-Butyl hydrogen monoperoxymaleate, 3015... 

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