Dimethyl (1-Diazo-2-oxopropyl)phosphonate

Used Chemicals

• Undecanal [U0009]
• Ohira-Bestmann Reagent [D3546]
• Potassium Carbonate [P1748]
• Methanol

Procedure

To a methanol (10 mL)　solution of undecanal (0.20 g, 1.2 mmol) was added potassium carbonate (0.32 g，2.4 mmol) and Ohira-Bestmann reagent (0.27 g, 1.4 mmol) at room temperature. The reaction mixture was stirred overnight at room temperature, then diluted with diethyl ether and washed with saturated aqueous sodium bicarbonate, and dried by sodium sulfate. The organic layer was concentrated under reduced pressure. The resulting crude product was purified by column chromatography (hexane:toluene = 3:1 on silica gel) to give 1 as a colorless liquid (0.11 g, 56% yield).

Experimenter’s Comments

The reaction mixtures were monitored by ¹H NMR (CDCl₃).

Analytical Data（1-Dodecyne (1)）

¹H NMR (400 MHz, CDCl₃); δ 2.18 (t, 2H, J = 7.1 Hz), 1.94 (s, 1H), 1.57-1.46 (m, 2H), 1.44-1.33 (m, 2H), 1.33-1.19 (m, 12H), 0.88 (t, 3H, J = 6.4 Hz).

¹³C NMR (101 MHz, CDCl₃); δ 85.0, 68.2, 32.0, 29.7, 29.7, 29.5, 29.3, 28.9, 28.6, 22.8, 18.5, 14.3.

Lead Reference

• Further Improvements of the Synthesis of Alkynes from Aldehydes
• G. J. Roth, B. Liepold, S. G. Müller, H. J. Bestmann, Synthesis 2004, 59.

Other References

• Methanolysis of Dimethyl (1-Diazo-2-oxopropyl) Phosphonate: Generation of Dimethyl (Diazomethyl) Phosphonate and Reaction with Carbonyl Compounds
• S. Ohira, Synth. Commun. 1989, 19, 561.

References

• K. Mohanan, A. R. Martin, L. Toupet, M. Smietana, J.-J. Vasseur, Angew. Chem. Int. Ed. 2010, 49, 3196.

References

• S. Ohira, Synth. Commun. 1989, 19, 561.
• S. Muller, B. Liepold, G. J. Roth, H. J. Bestmann, Synlett 1996, 521.
• H. D. Dickson, S. C. Smith, K. W. Hinkle, Tetrahedron Lett. 2004, 45, 5597.
• E. Quesada, R. J. K. Taylor, Tetrahedron Lett. 2005, 46, 6473.