4- butyl-2-methyl-4,5-dihydro

The mechanism of the acid-catalyzed decomposition of 1-alkyltriazolines has been studied <93JOC2097>. The hydrolytic decomposition of these triazolines in aqueous buffers leads predominantly to 1-alkylaziridines with lesser amounts of 2-(alkylamino)ethanol, alkylamines, and acetaldehyde. The rate of hydrolysis of 1-alkyltriazolines is about twice as fast as that of the analogous acyclic 1,3,3-trialkyltriazenes and varies in the order t-butyl > isopropyl > ethyl > butyl > methyl > propyl > benzyl <92JOC6448>. The proposed mechanism, involving rate-limiting formation of a 2-(alkylamino)ethyldiazonium ion, is shown in Scheme 65. A theoretical study ab initio calculation) of the acid-induced decomposition of 4,5-dihydro-l,2,3-triazolines has also been reported <91JA7893>. 

A solution of l-but-3-enyl-2,3-dihydro-li/-inden-l-ol (2.0 g (10.6 mmol) in rert-butyl methyl ether (350 mL) was irradiated in a quartz vessel with a 500-W high-pressure Hg lamp for 2.5 h. After workup, the yellow oil was separated by medium-pressure chromatography (hexane//err-butyl methyl ether 1 1) to give 0.45 g (23%) of 4 and 0.85 g (43%) of 5. 

Selective catalytic hydrogenation of the 6,7-double bond of 17/3-acetoxy-7-methylandrosta-4,6-dien-3-one was achieved with Pd-C-PhCH20H and gave the 7/8-methyl dihydro-compound. Added FeCls has been reported to improve the selectivity of reduction of a,/S-enones in metal-ammonia reactions, thereby improving the yield of the saturated ketones. Similar improvements were observed in the lithium-ethylamine reductions at -78 C when a substantial excess of lithium was used and t-butyl alcohol was the proton source. The influence of solvent and added nitrogenous bases on the stereoselectivity of hydrogenation of A - and A -3-oxo-steroids with Pd catalysts has been studied, and the stereoselectivity of Pd-catalysed hydrogenation of various A -7-oxo-steroids has been reported to be unaffected by substituents at C-3 or C-17. 

Imidazole, 4,5-dibromo-l-methyl-synthesis, S, 399 Imidazole, 4,5-di-t-butyl-synthesis, S, 483 X-ray diffraction, S, 350 Imidazole, 4,5-dichloro-chlorination, S, 398 synthesis, S, 398, 473 Imidazole, 4-(3,4-dichlorophenyl)-nitration, 5, 433 Imidazole, 4,5-dicyano-hydrolysis, S, 435-436 synthesis, S, 461, 472, 487 Imidazole, 4,5-dicyano-1-vinyl-synthesis, S, 387 Imidazole, 4,5-dihydro-mass spectra, 5, 360 Imidazole, 4-(dihydroxybutyl)-synthesis, S, 484 Imidazole, 4,5-diiodo-nitration, S, 396 synthesis, S, 400 Imidazole, 2,4-diiodo-5-methyl-iodination, S, 400 Imidazole, 1,2-dimethyl-anions... 

The A-ring of the 17-ol (25) derived from equilenin 3-methyl ether is reduced rapidly under Birch reduction conditions, since the 1,4-positions are unsubstituted. The B-ring is reduced at a much slower rate, as is characteristic of aromatic compounds in which 1,4-reduction can occur only if a proton enters an alkylated position. Treatment of (25) with sodium and t-butyl alcohol in ammonia reduces only the A-ring to afford the corresponding 1,4-dihydro compound in over 85% yield.On the other hand,... 

In the case of t-butyl substituted a,/3-unsaturated ketones, however, no reaction with ketones occurred in the presence of triphenylmethyl fluoroborate instead, a 1,2-methyl shift in the unsaturated ketone accompanied by cyclization afforded a crystalline dihydro-furylium salt. ... 

R = CII, methyl (K)-5-acetyl-2-to,n-butyl-2,3-dihydro-3-oxazolecarboxylate yield 25%... 

Benzopyran-3-one, l,4-dihydro-6,7-dimethoxy-], 55, 45 Isocyamde, benzyl-, 55, 98 Isocyanide, butyl-, 55, 98 ISOCYANIDE, tert-butyl- [Isocyamde, 1,1-dimethylethyl-], 55, 96 Isocyamde, cyclohexyl-, 55, 98 Isocyamde, dodecanyl-, 55, 98 Isocyamde, ethyl, 55,98 Isocyamde, methyl, 55, 98 Isocyamde, phenyl-, 55, 98 (-)-2,3 4,6-Di-0-isopropylidene-2-keto-L-gulomc acid, hydrate [L-jcy/o-2-Hex-ulosomc acid, bis-<9-( 1 -mcthylcthyl-ldene)-], 55,80, 81 ISOXAZOl F, 3-(4-chlorophenv1)-5-(4-methoxyphenyl)-, 55, 39 Isoxazole,5 -(4-chloropheny l)-3-(4-me th-oxyphenyl)-, 55,42... 

Benzoic acid, 1,1-dimethylethyl ester [Benzoic acid, fe/7-butyl ester] as impurity in /erV-butyllithium, 55, 125 Benzoic acid, 4 methoxy, methyl ester [Anisic acid, methyl ester], 55, 40, 41 3//-2-BENZOPYRAN-3-ONE, 1,4-dihydro-... 

Methyl-3-athyl-5-[2-thiocyanato-propyl-(2)]- 102 (2-Nitro-vinyl)- 79 2-(3-Oxo-buten-yl)- 722 2-(3-Oxo-butyl)- 722 5 -Oxo-2-me tliyl -4,5 -dihydro- 22 7... 

As reported by Padwa and coworkers, exposing a suitable nitrofuran precursor to microwave irradiation in l-methyl-2-pyrrolidone (NMP) in the presence of 2,6-luti-dine catalyst provided l,4-dihydro-2H-benzo[4,5]furo[2,3-c]pyridin-3-one as the major product in 36% yield (Scheme 6.236) [419]. In contrast, under thermal conditions, removal of the tert-butyl group was observed as the major reaction pathway. 

Synthesis of Enantiomerically Pure p-Amino Acid from 2-tert-Butyl-1-carbomethoxy-2,3-dihydro-4(1 H)-pyrimidinone (S)-p-Tyrosine-O-methyl Ether. 

Methylbutyl acetate, see sec-Amyl acetate 3-Methylbutyl acetate, see Isoamyl acetate 3-Methyl-l-butyl acetate, see Isoamyl acetate 3-Methylbutyl ethanoate, see Isoamyl acetate Methylbutyl ethyl ketone, see 5-Methyl-3-heptanone Methyl n-butyl ketone, see 2-Hexanone Methylcarbamate-l-naphthalenol, see Carbaryl Methylcarbamate-l -naphthol, see Carbaryl Methyl carbamic acid, 2,3-dihydro-2,2-dimethyl-7-... 

Plant The major degradation products of [2- C]terbacil identified in alfalfa using a mass spectrometer were (% of applied amount) 3-/er/-butyl-5-chloro-6-hydroxymethyluracil (11.9) and 6-chloro-2,3-dihydro-7-(hydroxymethyl)-3,3-dimethyl-5//-oxazolo[3,2-a]pyrimidin-5-one (41.2). Two additional compounds tentatively identified by TLC were 3-/er/-butyl-6-hydroxy-methyluracil and 6-chloro-2,3-dihydro-7-methyl-3,3-dimethyl-5//-oxazolo[3,2-a]pyrimidin-5-one (Rhodes, 1977). 

The second problem results from the fact that the azaenolates exist as aggregates or mixed aggregates in ethereal solvents. Cryoscopic measurements established that the azaenolate generated from 4,5-dihydro-4-methoxymethyl-2-methyl-5-phenyloxazole and butyllithium in tetrahydrofuran is a dimer18. When the metalation was performed with butyllithium or tert-butyl-lithium, an aging effect was observed. Thus, the enantiomeric excess on alkylation drops from 43% to 28% and 11 % when the azaenolates generated at — 78 °C were allowed to warm to... 

---