Diethyl Azodicarboxylate (40% in Toluene, ca. 2.2mol/L)

Used Chemicals

• N-(4-Methoxybenzyl)-o-nosylamide (1)
• Diethyl Azodicarboxylate (= DEAD, 40% in Toluene, ca. 2.2 mol/L) [A0705]
• cis-4-Hexene-1-ol [H0754]
• Triphenylphosphine (= PPh₃) [T0519]
• Toluene

Procedure

DEAD (40% in toluene, 1.06 mL, 2.33 mmol, 1.5 eq.) was added to a solution of 1 (500 mg, 1.55 mmol), triphenylphosphine (610 mg, 2.33 mmol, 1.5 eq.) and cis-4-hexene-1-ol (271 µL, 2.33 mmol, 1.5 eq.) in toluene (3.0 mL). The mixture was stirred for 2 hours at room temperature. After DEAD (0.71 mL, 1.56 mmol, 1.0 eq.) and triphenylphosphine (406 mg, 1.56 mmol, 1.0 eq.) were added and the reaction mixture was stirred for overnight. Then the mixture was concentrated under reduced pressure. The residue was purified by column chromatography (on silica gel, ethyl acetate:hexane = 0:100 – 25:75) and the fractions including 2 were collected. The residue was further purified by column chromatography (on silica gel, ethyl acetate:toluene = 0:100 – 10:90) to give 2 as a pale yellow oil (423 mg, 63% yield).

Experimenter’s Comments

The reaction mixture was monitored by TLC (ethyl acetate:hexane = 1:1, Rf = 0.78).
cis-4-Hexene-1-ol was treated in the draft chamber due to its bad smell.

Analytical Data

Compound 2

¹H NMR (270 MHz, CDCl₃); δ 8.01 (m, 1H), 7.74-7.62 (m, 3H), 7.24-7.17 (m, 3H), 6.84 (m, 2H), 5.40 (tqd, J = 1.1, 6.5, 10.5 Hz, 1H), 5.17 (qtd, J = 1.6, 7.3, 10.5 Hz, 1H), 4.46 (s, 2H), 3.80 (s, 3H), 3.20 (brt, J = 7.6 Hz, 2H), 1.86 (brq, J = 7.6 Hz, 1H), 1.51-1.38 (m, 5H).

Other Reference

• Chemoselective Hydrogenation Reaction of Unsaturated Bonds in the Presence of an o-Nitrobenzenesulfonyl Group
• A. Kawanishi, C. Miyamoto, Y. Yabe, M. Inai, T. Asakawa, Y. Hamashima, H. Sajiki, T. Kan, Org. Lett. 2013, 15, 1306.

References

• A New Method for Silylation of Hydroxylic Compounds: Reaction of Phenols and Alcohols with Silanols Mediated by Diethyl Azodicarboxylate and Triphenylphosphine
  • D. L. J. Clive, D. Kellner, Tetrahedron Lett. 1991, 32, 7159.
• Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols
  • P. G. M. Wuts, in Greene’s Protective Groups in Organic Synthesis, 5th ed., ed. by P. G. M. Wuts, John Wiley & Sons, Inc., Hoboken, New Jersey, 2014, Chap. 2, 17.

References

• Protection for the Hydroxyl Group, Including 1,2- and 1,3-Diols
  • P. G. M. Wuts, in Greene’s Protective Groups in Organic Synthesis, 5th ed., ed. by P. G. M. Wuts, John Wiley & Sons, Inc., Hoboken, New Jersey, 2014, Chap. 2, 17.