Butyl mesylate

Other Alkylation Experiments. In other experiments lithium and sodium were used in place of potassium. Biphenyl and anthracene were used in place of naphthalene. 1,2-Dimethoxyethane was used in place of tetrahydrofuran. Butyl chloride, butyl bromide, butyl mesylate, butyl triflate, methyl iodide, and octyl iodide were used in place of butyl iodide. The conditions used in these experiments were very similar to the conditions used in the procedures described in the previous paragraphs. The isolation procedure was modified in those cases where the ionic salt, e.g., sodium iodide, was soluble in tetrahydrofuran. In these instances the tetrahydrofuran-soluble product was washed with water to remove the salt prior to further study. 

Repetitive Alkylation Reaction. The tetrahydrofuran-insoluble materials, in certain instances, were subjected to a second alkylation reaction. In these cases there were three notable differences in the experimental results. First, the green color of the naphthalene radical anion and dianion persisted for a significantly longer time following the addition of the coal residue. Second, gas evolution, presumably butene-1, was detectable during the addition of butyl iodide or butyl mesylate but, significantly, not during the addition of methyl iodide. Third, the rate of formation of potassium iodide was much more rapid, such that the rate difference between butyl iodide and methyl iodide was not evident. 

In another experiment we tested the utility of 1,2-dimethoxyethane as a solvent for the reaction. The results obtained in this experiment revealed that the coal polyanion was formed to the same extent as in tetrahydrofuran. In addition, the alkylation of the polyanion with butyl mesylate gave the same quantity of soluble product in 1,2-dimethoxy-ethane as it did in tetrahydrofuran. Hence both solvents are equally useful for the alkylation reaction. 

An important question has yet to be answered are rr-complexed organometal systems capable of controlling the stereochemistry of 1,2 shifts The n-(arene) chromium tricarbonyl complexes of threo- and eryrfcro-3-phenyl-2-butyl mesylates, (900) and (901), and of e/7fhro-2-phenyl-3-pentyl mesylate (902) have been aceto-... 

O-isopropylidene derivative (57) must exist in pyridine solution in a conformation which favors anhydro-ring formation rather than elimination. Considerable degradation occurred when the 5-iodo derivative (63) was treated with silver fluoride in pyridine (36). The products, which were isolated in small yield, were identified as thymine and l-[2-(5-methylfuryl)]-thymine (65). This same compound (65) was formed in high yield when the 5 -mesylate 64 was treated with potassium tert-hx Xy -ate in dimethyl sulfoxide (16). The formation of 65 from 63 or 64 clearly involves the rearrangement of an intermediate 2, 4 -diene. In a different approach to the problem of introducing terminal unsaturation into pento-furanoid nucleosides, Robins and co-workers (32,37) have employed mild base catalyzed E2 elimination reactions. Thus, treatment of the 5 -tosylate (59) with potassium tert-butylate in tert-butyl alcohol afforded a high yield of the 4 -ene (60) (37). This reaction may proceed via the 2,5 ... 

C 3H,5N04 1148-11-4) see Angiotensinamide Captopril 7V-benzyloxycarbonyl-L-proline tert-butyl ester (C17H23NO4 16881-39-3) see Captopril 7V-benzyloxycarbonyl-L-serine (CiiHijNOj 7745-80-8) see Nelfinavir mesylate iV-benzyloxycarbonyl-L-serine-P-lactone (C Hi,N04 26054-60-4) see Nelfinavir mesylate 7V-benzyloxycarbonylsuccinimide... 

Pankova and Tichy prepared all four stereoisomeric 4-rerr-butyl-2-aminomethyl-l-cyclohexanols and cyclized them with ethyl benzimidate to hexahydro-l,3-benzoxazines 158-161 (74CCC1447). From the A-acyl O-mesylate derivatives 162 and 163 on thermal cyclization or thionyl chloride treatment, ring closure occurred with inversion and resulted in 158 and 159 (74CCC1447). 

The CD fragment 1s synthesized starting with resolved bicyclic acid 129. Sequential catalytic hydrogenation and reduction with sodium borohydride leads to the reduced hydroxy acid 1. The carboxylic acid function is then converted to the methyl ketone by treatment with methyl-lithium and the alcohol is converted to the mesylate. Elimination of the latter group with base leads to the conjugated olefin 133. Catalytic reduction followed by equilibration of the ketone in base leads to the saturated methyl ketone 134. Treatment of that intermediate with peracid leads to scission of the ketone by Bayer Villiger reaction to afford acetate 135. The t-butyl protecting... 

Reaction of the anion of tert-butyl isocyanoacetate with oxiranes gives the y-hydroxy products 11, which upon mesylation can be transformed by an intramolecular alkylation to the iso-cyanocyclopropanecarboxylates 12, the precursors of 1-amino-cyclopropanecarboxylates100. The cyclization 11 — 12 shows a relatively high degree of stereoselectivity due to the difference in bulkiness betwen the isocyano and the tert-butoxycarbonyl groups. 

An alternate method for building the partly saturated fused heterocyclic system for ticlopidine (10-4) starts by formation of the mesylate (11-2) from cyanopyridone (11-1) by treatment with methanesulfonyl chloride. The reaction of that with butyl thioglycolate can be envisaged as involving, first, the addition of the thiol group to... 

Preparation of the Living" Polystyrene. 18 g of the living polymer was prepared by standard anionic polymerization using n-butyl lithium. The reaction was carried out by the dropwise addition of 20 ml of styrene to 5 ml of the initiator solution in 150 ml of neat THF at -78°C. The styrene drip was adjusted to take approximately 30 min for completion and then the reaction was allowed to stir for two hours before the grafting reaction with mesylated lignin was carried out. The number average molecular weight of the polystyrene, as determined by HPSEC, was 9500 with polydispersity of 1.2. 

Quallich and Woodall described the first asymmetric synthesis utilizing a catalytic enantioselective reduction of the ketoester 35 with (S)-terahydro-l-methyl-3,3-diphenyl-lH,3W-pyrrolo[l,2-c][l,3.2]oxazaborole (CBS) to give the desired hydroxyester 36 (90% ee). After mesylation, Sn2 displacement with a higher-order cuprate derived from copper cyanide gave the diaryl r-butyl ester 37 with good chirality transfer. Intramolecular Friedel-Crafts cyclization gave the tetralone 31 in 90% ee (Scheme 7). ... 

P-Lactams The mesylate (1) of N-(phenylacetyl)serine O-benzylhydroxa-mate can be cyclized directly to 2 in 75% yield by potassium t-butoxide (1 equiv.) in t-butyl alcohol at -23°. Use of KHC03 results in the oxazoline 3 in 94% yield. 

Treatment of the derived mesylate with potassium tert-butoxide in ter/-butyl alcohol resulted in smooth and efficient conversion to... 

The is-olefin was prepared as a trans-amide bond replacement. A number of compounds incorporating substituents to mimic both natural and unnatural amino acid sidechains were prepared by adapting chemistry developed by Ibuka for the synthesis of Zs-olefin peptide isosteres (see Scheme l).40,41 The key step involved anti-SN2 displacement of vinyl mesylate 8 by boron trifluoride-activated cuprate addition. Compounds containing butyl, propyl, and benzyl substituents at the allylic positions to mimic the aj and sidechains produced potent FTase inhibitors (Table 4). 

S)-l-[2-Hydroxy-4-(4-chlorophenyl)butyl]-lH-imidazole nitrate was prepared as follows. To a solution of (2S)-l-(p-toluenesulphonyloxy)-4-(4-chlorophenyl)butan-2-ol (250 mg, 1 mmol) in THF (5 ml) at 0°C was added triethylamine (0.28 ml, 2.0 mmol), followed by methanesulfonyl chloride (0,15 ml, 2.0 mmol). The reaction mixture was was warmed to room temperature and stirred for 1 h. The mixture was poured into aq. NaHC03, extracted with EtOAC, and the organic phase dried and evaporated to dryness. The resulting mesylate was dissolved in acetone (50 ml), then 2,6-dichlorobenzenethiol... 

The salt of saquinovir mesylate was obtained by the reaction of N-tert-butyl-decahydro-2-[2(R)-hydroxy-4-phenyl-3(S)-[[N-(2-quinolylcarbonyl)-L-asparaginyl]amino]butyl]-(4aS,8aS)-isoquinoline-3(S)-carboxamide with monomethanesulfonic acid. 

Preparation of Cellulose-Polystyrene Graft Copolymers. The polystyr-yl mono- and di-carbanions were prepared in THF at -78 °C by using n-butyl lithium and sodium naphthalene as the initiators, respectively. The carban-ions were reacted with dry carbon dioxide. The products were precipitated in methanol, filtered, washed with water and methanol, and dried. Size exclusion chromatography (SEC) established that the molecular weight of the polystyryl monocarboxylate was 6,200 and that of the polystyryl di-carboxylate 10,2000. The mono- and di-carboxylates were reacted with mesylated cellulose acetate in dimethylformamide at 75 °C for 20 h to give the cellulose-polystyrene graft copolymer (GP 1) and crosslinked cellulose-polystyrene graft copolymer (GP 2), respectively. 

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