N,N-dimethylmethanamine oxide

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 400 ml of 0.5 M bis-(3-methyl-2-butyl)borane in glyme, prepared from sodium borohydride, 2-methyl2-butene, and boronitrifluoride etherate as in Example 107, is added 63.7 g (0.30 moles) of 4-methyl-4-trimethylsilyloxy-1-octyne (Example 125) at -10° C. The solution is stirred at ambient temperature for 2.5 hours, cooled to -10° C., and treated during 30 minutes with 158 g (2.1 moles) of solid trimethylamine oxide with cooling. The mixture is stirred at ambient temperature for 2 hours and then poured into a stirred, ice-cold solution of 15% aqueous sodium hydroxide; the stirred mixture is treated immediately with a solution of 426 g (1.68 moles) of iodine in 1100 ml of tetrahydrofuran, After 4 hours the mixture is extracted with ether. The extract is washed successively with water, aqueous sodium thiosulfate, and brine and dried over magnesium sulfate. The extract is concentrated, and the residue is subjected to chromatography on silica gel with hexane to provide an oil, p.m.r. (CDCl3): δ 1.18 (singlet, 4-CH3 group). cooled to -10° C. with cooling The mixture is stirred at ambient temperature for 2 hours is extracted with ether The extract is washed successively with water, aqueous sodium thiosulfate, and brine dried over magnesium sulfate The extract is concentrated to provide an oil, p.m.r

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 0.20 moles of freshly prepared bis-(3-methyl-2-butyl)borane in 300 ml of tetrahydrofuran at 0°-5°C is added dropwise a solution of 19.8 g of 4-trimethylsiloxy-1-octyne in 30 ml of tetrahydrofuran. The resulting mixture is stirred at ambient temperature for several hours, cooled in an ice bath, and treated with 53 g of trimethylamine oxide. The mixture is stirred several hours at 25°- C. C. and then poured into 2 liters of 15% sodium hydroxide. The resulting mixture is treated immediately with a solution of 140 g of iodine in 300 ml of tetrahydrofuran. After 0.5 hour the organic phase is separated and the aqueous phase is extracted with ether. The combined organic layers are washed with water, sodium thiosulfate solution, and brine; dried over magnesium sulfate; and concentrated to give an oil, pmr spectrum (CDCl3): 6.2 (d, ICH=) and 6.7 (quintuplet, =CH--). cooled in an ice bath The mixture is stirred several hours at 25°- C After 0.5 hour the organic phase is separated the aqueous phase is extracted with ether The combined organic layers are washed with water, sodium thiosulfate solution, and brine dried over magnesium sulfate and concentrated to give an oil, pmr spectrum (CDCl3)