5-oxo-7-trimethylsilylhept-6-ynoic acid

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A in 750 mL of IPA under an atmosphere of nitrogen was added 33.6g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

Conditions: temp:45.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The known 5-oxo-7-(trimethylsilyl)hept-6-ynoic acid (1.15 g, 2; prepared using the procedure described in J. Org. Chem., Vol. 62, No. 4, 1997, pp. 982-991) was dissolved in methanol (40 ml) and a solution of Borax (Na2B4O7×10H2O, 2.7 g) in water (6 ml) was added. The resulting reaction mixture was stirred for 18 h at 45° C. under argon. The reaction mixture was then quenched by the addition of 1 M HCl (20 ml) and methanol removed in vacuo. The remaining aqueous solution was then extracted with ethyl acetate (4×35 ml). After washing the pooled organic extracts with brine (2×40 ml), drying with MgSO4 and then filtering, volatiles were removed in vacuo. The crude orange oil remaining was purified by flash chromatography (5% ethyl acetate→10%→15% ethyl acetate/hexane) yielding a pale yellow oil product, 5-oxohept-6-ynoic acid (328 mg, J), which crystallized under storage. 1H NMR (400 MHz, CDCl3): δ1.75 (m, 2H), 2.22 (t, 2H), 2.63 (t, 2H), 4.8 (s, 1H). prepared The resulting reaction mixture The reaction mixture was then quenched by the addition of 1 M HCl (20 ml) and methanol removed in vacuo The remaining aqueous solution was then extracted with ethyl acetate (4×35 ml) After washing the pooled organic extracts with brine (2×40 ml) drying with MgSO4 filtering volatiles were removed in vacuo The crude orange oil remaining was purified by flash chromatography (5% ethyl acetate→10%→15% ethyl acetate/hexane)

Conditions: temp:45.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The known 5-oxo-7-(trimethylsilyl)hept-6-ynoic acid (1.15 g, 2; prepared using the procedure described in J. Org. Chem., Vol. 62, No. 4, 1997, p. 982-991) was dissolved in methanol (40 ml) and a solution of Borax (Na2B4O7×10H2O, 2.7 g) in water (6 ml) was added. The resulting reaction mixture was stirred for 18 h at 45° C. under argon. The reaction mixture was then quenched by the addition of 1 M HCl (20 ml) and methanol removed in vacuo. The remaining aqueous solution was then extracted with ethyl acetate (4×35 ml). After washing the pooled organic extracts with brine (2×40 ml), drying with MgSO4 and then filtering, volatiles were removed in vacuo. The crude orange oil remaining was purified by flash chromatography (5% ethyl acetate→10%→15% ethyl acetate/hexane) yielding a pale yellow oil product, 5-oxohept-6-ynoic acid (328 mg, 3), which crystallized under storage. 1H NMR (400 MHz, CDCl3): δ1.75 (m, 2H), 2.22 (t, 2H), 2.63 (t, 2H), 4.8 (s, 1H). prepared The resulting reaction mixture The reaction mixture was then quenched by the addition of 1 M HCl (20 ml) and methanol removed in vacuo The remaining aqueous solution was then extracted with ethyl acetate (4×35 ml) After washing the pooled organic extracts with brine (2×40 ml) drying with MgSO4 filtering volatiles were removed in vacuo The crude orange oil remaining was purified by flash chromatography (5% ethyl acetate→10%→15% ethyl acetate/hexane)

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles

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

Procedure: To a stirred solution of 54.0 g (254 mmol) of 7-(trimethylsilyl)-5-oxohept-6-ynoic acid from step A above in 750 mL of IPA under an atmosphere of nitrogen was added 33.6 g (254 mmol) of tert-butyl carbazate. The reaction mixture was stirred for 4 h at ambient temperature then evaporated in vacuo to remove all volatiles. This afforded the title compound as a yellow gum which was used without further purification (77 g, 93%). LC-MS: m/z (ES) 327 (MH)+. then evaporated in vacuo to remove all volatiles