Methyl inflate

The synthesis of this derivative of KDG was accomplished following the sequence depicted in figure 6. Methylation of the intermediate 8 with methyl Inflate afforded compotmd 21. Subsequent removal of the enol benzoate group at C-2 and of the silyl ether at C-6 provided the target compound 23 in 11% overall yield based on 8. This low yield could be due to the unstability of compotmds 8, 21 and 22 in a basic medium. However 24 was obtained in quantity sufficient for testing. 

Methyl Inflate Methyl trilluoromethanesuHonate Methanesulfonic acid, trifluoro-, methyl ester (8.9) (333-27-7)... 

Methyl ethers are usually prepared by some variant of the lliamson ether synthesis in which an alcohol reacts with either iodomethane. dimethyl sulfate, or methyl inflate (HAZARD) in the presence of a suitable base. A word of caution dimethyl sulfate and methyl triflate, like all powerful alkylating agents, are potentially carcinogenic and therefore should only be handled in a weil-ven-tilated fume hood. For the O-methylation of phenols (pKa 10) a comparatively weak base such as potassium carbonate in conjunction with dimethyl sulfate is sufficient, whereas simple aliphatic alcohols require stronger bases such as sodium hydride [Scheme 4.111] or lithium hexamethyldisilazide [Scheme 4.112]. The latter transformation is notable for the fact that O-methylation was accomplished without competing elimination. 

Vinyl Inflates permit alkylation with vinyl cations [24, 25] Fluorobenzene reacts with 2 methyl 1-phenyl 1 propenyl triflate to form a diaryl alkene [24J (equation 17)... 

Using the same initial step for the double serial inversion strategy, from methyl glucoside 37, the 2,4-tiiflate intermediates 50 could be produced via a Inflation process (Scheme 15). The 4-triflates of these intermediates were subsequently inversed to the corresponding 4-0-acetyl intermediates 51 by substitution with tetrabutylammonium acetate, followed by inversion of the 2-position by tetrabutylammonium nitrite, to yield a mixture of methyl... 

Conversion of bromohydrins to alkenes. The 14,15-epoxide (1) of arachidonic acid methyl ester has been converted into the 11,12-epoxide (5) in two steps. The first is conversion of 1 into a mixture of isomeric bromohydrins (2 and 3) with KBr. The mixture is then epoxidized under the conditions of Sharplcss (5, 75 76) to give, after chromatographic purification, 4, the epoxide of 2. Conversion of 4 into 5 presented a problem, but was eventually achieved by treatment of the w c-bromo Inflate with P[N(CHj)2]j as a Br acceptor. 

Imino and iminium inflates derived from secondary and tertiary amides respectively, react with l,l,l-2-hydroxymethyl-2-methyl-propane-l,3-dioJ in the presence of pyridine to give the OBO derivative [Scheme 2.112],234 Primary amides cannot be used as substrates because they dehydrate to the nitrile under the reaction conditions. 

At low temperature (-78 C) deprotonation with the bulky silyl amide KHMDS nins under kinetic control - enolization takes place regio-and stereoselectivcly at the terminal methyl group of ketone 4. The sterically less hindered enolate is transformed to enol Inflate 22, which has M-trans configuration. 

Syn 3-(Ethylth(oniethyl)-4-hydroxy-6-phenyl>2-hexanone (4) and amt (5) 3 To emanethwi (to 0 mg 0 17 mmol) in the (2 mL) was added 1 54 M n butyliithwm in hexane (0 11 mU at 0°C under Ar Stannous Inflate (69 0 mg 0 17 mmol) was added and alter 20 mm the mixture was cooled to 45°C Methyl vinyl Ketone 1 (118 mg 1 98 mmol) m THE 1 5 mL) was added followed by 3 phenylpropanal 3 (350 mg 2 61 mmol) in THE (1 5 mL) Alter 12 h aq cilnc acid was added and the organic material extracted with CHjCia The resxlue after evaporation was dissolved in MeOH and treated with citric acid After 30 mm stimng. the mixture was quenched with pH 7 phosphate buffer extracted with CH2CI2, the solvent evaporated and the residue chromatographed to afford 336 mg of 4 (75%), syn anti (90 10)... 

Dialkylboron trifluoromethanesulfonates (Inflates) are particularly useful reagents for the preparation of boron enolates from carbonyl compounds, including ketones, thioesters and acyloxazolidinones." Recently, the combination of dicylohexylboron trifluoromethanesulfonate and triethylamine was found to effect the enolization of carboxylic esters. The boron-mediated asymmetric aldol reaction of carboxylic esters is particularly useful for the construction of anti p-hydroxy-a-methyl carbonyl units. The present procedure is a slight modification of that reported by Brown, et al. ... 

The ran -aminocarbyne(iodo)tungsten complexes 125 react with CF3SO3CH3 to give the inflate derivatives 126 and methyl iodide [Eq. (106)] 138). This reaction is a rare example of direct attack of electrophiles at the trans halide ligand of a carbyne complex. 

Because of the preferred linearity of vinyl cations, the stability of cyclic vinyl cations depends on the ring strain or the ring size. Rates of solvolysis of Inflates show that the 1-cyclohexenyl cation is 6 X 10 -fold less readily generated than the 1-methyl-1-propenyl cation. The 1-cyclopentenyl cation is not formed at all. On the other hand, 1-cyclobutenyl triflate is 3700 times more reactive than 1-cyclohexenyl triflate.The stability of the cyclobutenyl cation is due to resonance involving cyclopropyl-stabilization of the positive charge. ... 

YOS 10b] Yoshida E., Nitroxide-mediated photo-living radical polymerization of methyl methaciylate using (4-tert-butylphenyl)diphenylsulfonium inflate as a photo-acid generator . Colloid and Polymer Science, vol. 288, pp. 239-243, 2010. 

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