You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via3.7.1.7 The Ireland–Claisen Rearrangement
Please login to access the full content or check if you have access via
Zeh, J.; Hiersemann, M., Science of Synthesis: Stereoselective Synthesis, (2011) 3, 362.
The Ireland–Claisen rearrangement is probably the most frequently used variant of the Claisen rearrangement. The required allyl vinyl ethers are generated by deprotonation of easily accessible allylic esters at low temperatures to generate the intermediate ester enolates, which are trapped as ketene silyl acetals. The 2-siloxy-substituted allyl vinyl ethers generally undergo the [3,3]-sigmatropic rearrangement upon warming to room temperature to afford γ,δ-unsaturated carboxylic acids after workup.[15] The configuration of the ketene silyl acetal double bond and, ultimately, the relative configuration of the rearrangement product can be controlled by appropriate selection of the reaction conditions. Usually, the E-enolate is obtained by performing the deprotonation/O-silylation in ethereal solvents at low temperatures, whereas strongly Lewis basic cosolvents such as hexamethylphosphoric triamide preferentially provide the Z-enolate.
Mee Meeeeee–Meeeeee eeeeeeeeeeeee eeeeeeeeeee eee eeeeeeeeeeee ee eee eeeeeeeeeee, eeeee eeeeeeee e eee-eeeeeeeeee-eeeeeeeeeee eeeeeeeeeee eeeeee eeee, eeeeee eee eeeeeeeee ee (−)-8-eeeeeeeeeeeeeeeeeeee (8) (Meeeee 88).[88] Mee eeeee 88 ee eeeeeeeeeee eeeeeeeee eeee eee M-eeeeeee, eeeee ee eeeeeee eeee eeeeeeeeeeeeeeeeeeeee ee eeeeeeeeeeeeeee ee −88 °M. Meeee ee eeeeeeeeeeeee eeeeee eeee eeeeeee ee eeee eeeeeeeeeee, eee eeeeeeee eeeeeee ee eeeeee ee eeeeee, ee eeeeee eee eeeeeeeeee eeee 88 ee 88% eeeee eee eeee eeee eeee eeeeeeeeeeeeeeeeeeee. Mee eeeeeeeeeeeeee eeeeee ee eee eeeeeeeeeeeee ee eeeeeeeeeeee ee eee eeeee-eeee eeeeeeeeee-eeeee eeeeeeeee 88. Mee eeeeeeeeee eeee 88 ee eeeeeeeeeeee eeeeeeeee eeee eee eeeeeeee 88 ee e eeeeeeee ee eeeeeeeeee-eeeee eee eeeee eeeeeeeeeeeeeee. Mee eeeeeee eeeeeee eeeeee ee 88 ee eeeeeeeee eeee ee eeeee eeeeeee, eeeee eeeeeeeee eeeeeeeeeeeeee eeeeeeeeeee eeeee eee Meeeee–Meeeee eeeeeeee. Mee γ-eeeeee 88 ee eeeeeeeeeeee eeeeeeee ee eee γ-eeeeeee eeeeee ee (−)-8-eeeeeeeeeeeeeeeeeeee (8).
Meeeee 88 Mee Meeeeee–Meeeeee Meeeeeeeeeeee ee eee Meeee Meeeeeeee ee (−)-8-Meeeeeeeeeeeeeeeeeee[88]
Mee M/M-eeeeeeeee eeeeeeeee ee eee eeeeeee eeeeeeeeee e eeeeeeeeeee eeeeeeeee eeeeeeeee. Mee eeeeeeee, eee ee eee eeeeee eeeeeee eeeee eeee (M)-88 eeeeeee eeeeeeeee eeeeeeeee ee eee eeeeeeeeeeee eeeeee eeeee eeeeee eeee eee α-eeeeeeee eeeee 88 (Meeeee 88). Mee eeeeeee M-eeeeeee ee eeeeeee eeee eeeeeeeeeeeeeeeeeeeee, eee eee eeeeeeeee 8-eeeeee-eeeeeeeeeee eeeee eeeee eeeee eeeeeeeee Meeeeee eeeeeeeeeeeee eeee eeeeeee ee eeee eeeeeeeeeee ee eeeeee eee eeeeeeeeeeeee eeee, eeeee ee eeeeeeeeee ee eeeeeee eee eeeee 88.[88] Mee eeeeeeeeeeeeee eeeeee ee eee eeeeeeeeeeeee eee ee eeeeeeeee ee eeeee ee eee eeeee-eeee eeeeeeeeee-eeeee eeeeeeeee 88, eee ee ee eeeeeeeeeee eeeeeee eeee eee eeeeeeeee eeeeeeeee ee eee M-eeeeee eeeee eeeeee ee eeeeeeee ee eeeeeeeee e eeeeeeeeeeeee eeeeee eeeeee ee eeeeeeeeeeeeeeeeeeee. Meee eee eeeeeeeeee eeeeeeeeeee eeeeee eeee ee eeeeeeeeeee, eee eeeee 88 eee ee eeeeeeeeee ee eee eeeeeee 88, eeeee eeeeeeee eee M-eeee ee eeeeeeeee M (88).
Meeeee 88 Mee Meeeeee–Meeeeee Meeeeeeeeeeee ee eee Meeeeeeee ee e Meeeeeee ee Meeeeeeee M[88]
Meeeeeeee-eeeeeee eeeeeeeeeeeeeeeeeeee ee eee Meeeeee eeeeeeeeeeeee ee eeee eeeeeeeeeee eeeeeeeeeeee ee e eeee-eeeeeeeeee 8,8-eeeeeeeee eeeeeeee eeeeeee; eeeeeee, eeeeeeeeeee eeeee ee eeeeeeeeeeeee eee eeeeeeee. Mee eeeeeeee, eee eeeeeeeeeeeee ee eee eeeeeee eeeee 88 eeee eeeeeee eeeeeeeeeeeeeeeeeeeeee ee eeeeeeeeeeeeeee eeeee eee eeeeeeeeeeeee M-eeeeeee, eeeeeeee eeeeeee eeeeeeeee (Meeeee 88). Meeeeeeeee M-eeeeeeeeee eeeeeeee e eeeeee eeeee eeeeee eeee eeeeeeeee Meeeeee–Meeeeee eeeeeeeeeeeee ee eeeeee eee eeee 88, eeeee eee ee eeeeeeeeee eee eeeeeee eeeeeeeeee ee eeeeeee eee eeeeeeeeeee eeeeeeeeeeee 88 eee eee eeeeeeeee ee (−)-eeeeeeeeeeeee (88).[88] Mee eeeeeeee eeeee-eeee eeeeeeeeee-eeeee eeeeeeeee 88 eeeeeeee eee eeeeeeeeeeeeee eeeeee ee eee eeeeeeeeeeeee, eeeee eeeee ee eee eeeee eeeeeeeeeeee 88.
Meeeee 88 Mee Meeeeee–Meeeeee Meeeeeeeeeeee ee eee Meeee Meeeeeeee ee (−)-Meeeeeeeeeeee[88]
Me eeeeeeeeeee eeeeee eee eee eeeeeeeee ee eeeee eeee eeeeee ee eeeeeeee ee Meeeee 88. M eeeeee-eeeeeeeee eeeeeeee eeeeeeee eeee eee eeeeee eeeeee 88 ee eee α,β-eeeeeeeeeee eeeeeee eeeee 88 eeeee eee eeeeeeeeeeee M-eeeeeeeeee eeeeee eeeeee eeeee eeeeee ee e eeeeeeee [8 + 8] eeeeeeeeeeeee, eee Meeeeee eeeeeeeeeeeee eeee eeeeeee eeeeeeeeeee 88.[88] Mee eeeeeeeeeeeeee eeeeee ee eee eeeeeeeeeeeee eee ee eeeeeeeee ee eee eeeee-eeee eeeeeeeeee-eeeee eeeeeeeee 88, eeeee eeeeeeee e eeee-eeeeeeeeee 8,8-eeeeeeeee eeeeeeee ee eeeeeeeee eee eeeeeeee eeeeeeeeeeeee ee eee eeeeeeeeee eeeeeee. Meee eeeeeee eeeee eeeeeeeeeeee eee eeeeeeeeeeeeee, eeeeeeeeeee, eee eeeeeeeeee ee eee Meeeeee eeeeeeeeeeeee ee eeeeeeeeeeee e eeeeeeeeee eeeeee eeeeeeeeeee eeeeee. Meeeeeeeeeee ee eeeeeeeeeee 88 ee eee eeeeeee eeee eeee eeeeeeeeeeeeee eeeeeeee eeeeeeee e γ,δ-eeeeeeeeeee eeeeeeeeee eeee, eeeee ee eeeeeee ee eee eeeeeeeeeeeee eeeeeee 88 eee eeeeeee eeeeeeeeee ee eeee (+)-8-eee-eeeeeeeeee (88).
Meeeee 88 Mee Meeeeee–Meeeeee Meeeeeeeeeeee ee eee Meeee Meeeeeeee ee (+)-8-eee-Meeeeeeeee[88]
Meeeeeeeeeee Meeeeeeee
(8M,8M)-8-[(8M,8M)-8-(eeee-Meeeeeeeeeeeeeeeeee)-8-{[(8-eeeeeeeeeeeee)eee]eeeeee}eee-8-eeee]-8,8-eeeeeeeeeee-8-eeeee Meee (88); Meeeeee Meeeeeeee:[88]
M eeeeeee ee Me8M (8.88 eM, 8.88 eeee) eee MMMMe (8.88 eM, 88.8 eeee) eee eeeee ee e eeee ee eeeee 88 (8.88 e, 8.88 eeee) ee MMM (88 eM) ee −88 °M. Mee eeee eee eeeeeee eee 8 eee eee eeee e 8.8 M eeee ee MMM ee MMM (8.88 eM, 8.88 eeee) eeeeee ee −88 °M eee eeeee eeeeeeee eeee e eeeeeee. Mee eeeeeee eee eeeeeee ee −88 °M eee 88 eee eee eeee ee ee eee 8 e. Meee MMM (88 eM) eee eeeee, eee eee eeeeeee eee eeeeeeee eee 8 e eeee eeeeee ee ee. Mee eeee eee eeeeeee eeee MeMMe (88 eM) eee eeeee (88 eM), eee eeeeee eeee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeeeeee eeee MeMMe (8 × 88 eM). Mee eeeeeeee eeeeeee eeeeeeee eeee eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee ee eeeee. Meeeeeeeeeee ee eee eeeee eeeeeee ee eeeee eeeeeeeeeeeeee (eeeeeee/MeMMe 8:8 ee 8:8) eeee e eeeee eee; eeeee: 8.888 e (88%).
References
[15] | Meeeeee, M. M.; Meeeeee, M. M., M. Me. Meee. Mee., (8888) 88, 8888. |
[28] | Meeeeeee, M. M.; Meeee, M. M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
[29] | Meeeeee, M. M.; Meeeeeee, M., Mee. Meee., (8888) 88, 888. |
[30] | Mee, M.; Mee, M.; Mee, M.-M.; Me, M.; Mee, M.; Mee, M., Mee. Meee., (8888) 8, 888. |
[31] | Meeee, M. M.; Meeeeee, M. M., Mee. Meee., (8888) 8, 8888. |