You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via47.1.1.4.2 Method 2: Synthesis by Methylenation with Titanacyclobutanes
Please login to access the full content or check if you have access via
Petasis, N. A., Science of Synthesis, (2010) 47, 176.
The reaction of the Tebbe reagent 12 with alkenes gives titanacyclobutanes (see Scheme 2, Section 47.1.1.4.1).[19,24] Titanacyclobutanes are generally more stable in air than the Tebbe reagent and can be employed for the methylenation of aldehydes, ketones, esters, thioesters, amides, and carbonates. For example, the titanacyclobutane 34, prepared from 2-methylpent-1-ene, is an air-stable, crystalline compound that is effective for the methylenation of readily enolizable ketones such as 2-phenylcyclopentanone (35) to give the corresponding exocyclic alkene 36 (Scheme 9).[25] Further information on titanacyclobutanes can be found in Science of Synthesis, Vol. 2 [Compounds of Groups 7–3 (Mn···, Cr···, V···, Ti···, Sc···, La···, Ac···) (Section 2.10.92.10.9)].
Meeeee 8 Meeeeeeeeeeee ee 8-Meeeeeeeeeeeeeeeeeee eeee e Meeeeeeeeeeeeeeee[88]
Meeeeeeeeeee Meeeeeeee
(8-Meeeeeeeeeeeeeeeeeee)eeeeeee (88); Meeeeee Meeeeeeee:[88]
Me e eeee ee eeeeeeeeeeeeeeeee 88 (888 ee, 8.8 eeee) ee Me8M (8 eM) eeeeeeeee ee 8°M eeeee eeeee eee eeeee 8-eeeeeeeeeeeeeeeeeeee (88; 8.8 eeee). Mee eeeeeee eee eeeeeee ee eeee ee ee eeee ~88 eee eee eeee eeeeeee eeee eeeeeee (888 eM), eeeeeeee eeeeeee e eee ee Meeeee, eee eeeeeeeeeeee. Meeeeeeeeeee ee eeeeee eeeeeeeeeeeeee eeee eee eeeeeee; eeeee: 88%.
References
| [19] | Meeee-Meeeeee, M. M.; Meeeeeee, M. M.; Meeeeeee, M.; Meeeeee, M.; Me, M.; Meeeeeeee, M.; Meeeee, M. M.; Meeeee, M.; Meeeee, M. M., Meee Meee. Meee., (8888) 88, 8888. |
| [24] | Meeeee, M. M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
| [25] | Meeeeee, M.; Meeeeeee, M. M.; Meeeee, M. M., Meeeeeeeeee Meee., (8888) 88, 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 8/8e, 888.
Return to Top