2,3-dimethylbut-2-ene

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 0.06 mol CSI (chlorosulfonyl isocyanate) in dry ether under nitrogen, 0.06 mol of 2,3-dimethyl-but-2-ene was added dropwise at a temperature of 30° to 35° C. The reaction mixture was stirred for a further 1 hour while it was cooled to room temperature. The solution was then cooled in a salt-ice bath and the product which crystallized out as white solid was filtered off and carried through to the next step. The solution was then cooled in a salt-ice bath the product which crystallized out as white solid was filtered off

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

Procedure: A 10 mL round-bottomed flask was charged with 5-carbon linked dimer alcohol (57 mg, 0.0885 mmol) in 1 mL of THF. To the reaction mixture was added thexylborane (0.8 mL, 3 eq.) 0.33M in THF solution obtained from BH3THF (1 eq) and 2,3-dimethyl-2-butene (2 eq) at 0° C. for 1 hr. The reaction mixture was stirred for 2 hr and then added 3 N NaOH (0.15 mL, 5 eq) and 30% H2O2 (0.15 mL, 5 eq). The reaction mixture was warmed to room temperature and then stirred for 12 hr. The reaction mixture was quenched with H2O, extracted with EtOAc, dried over MgSO4 and concentrated. The crude product was purified by column chromatography (EtOAc/Hexane=3/1) to give 39.2 mg in 65% yield.

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

Procedure: The method of Mesheheryakov, Chem. Abstr., 54, 24436d (1960) was employed. To a mixture of 19 g. (0.226 mole) of 2,3-dimethyl-2-butene and 2 g. of cupric sulfate is added at reflux a mixture of 51 g. (0.447 mole) ethyl diazoacetate and 19 g. of 2,3-dimethyl-2-butene. The resulting mixture is heated at reflux for 3 hours, cooled, filtered and distilled to afford 19.8 g. (26%) of the desired cyclic ester, B.P. 76°-77° (15 mm.) To a mixture of 19 g at reflux a mixture of 51 g The resulting mixture is heated at reflux for 3 hours cooled filtered distilled to afford 19.8 g