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Please login or sign up for a free trial to access the full content. Method 4: Synthesis by Methylenation with gem-Dimetallic Reagents

DOI: 10.1055/sos-SD-047-00100

Petasis, N. A.Science of Synthesis, (201047204.

Several types of reaction involving gem-dimetallic (1,1-dimetallic) reagents are known.[‌142‌] The methylenation of carbonyl compounds to produce alkenes is possible by a number of methods involving these reagents, particularly those containing combinations of zinc, titanium, or magnesium halides (Scheme 26). gem-Dimetallic reagents are typically able to methylenate aldehydes, ketones, and, in some cases, esters and lactones.

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Meeee eeee eeeeeeeeee 888 (M=Me, M) eeeee eeee eeeeeee ee eeee eeeeeeeeeeeee, eee eee-eeeeeeeeeee 888 (M=Me, M) eeeee eeee eeeeeeee eeeeeeeee ee eeee eeeeeee. Me eeeee ee eeeeeeeeee eee eeeeeeeeeeeee eeeeeee, e eeeeee ee eeeeeeeeeeeee eeee eeee eeeeeeeee eeee eeeeeeeeee eee eeeeeeeeee ee eee eeeeeeeeee 888 eeee eee eee-eeeeeeeeeee 888. Meeee eeeeeee eee eee ee eeeeeeeeee[‌888‌] ee eeeeee eeeeeeee eeeee,[‌888‌,‌888‌] eee ee e eeeeeeee eeeeee[‌888‌] ee eeee eeeeeeeeee eeeeeeeee eeeeeee ee eeee,[‌888‌] ee eeeeeeee ee eeee(MM) eeeeeeee ee e eeeeeeee.[‌888‌,‌888‌] Mee eeeeeeeee eeee ee eeee ee eeeeeeee ee eee eeeeeeeee ee eee-eeeeeeeeeee 888 eee eeee eeeeeeeeee ee eee eeee eeeeeeeeeeeeeee ee eeee eeeeeeeeee 888 ee eeee eeee eeeeeeeeee 888, eeeee eeeeeee ee eeee eeee eeeee eeeeeeee eeee eeee ee eeee eeeee eee-eeeeeeeeeee 888. Meeee eeeee-eeeee eeeeeeeeeeeee eee eeee eeeeeeeee eeee eee-eeeeeeeeeee 888 ee eeeeeeeeeeee ee eee eeee(MM) eeeeee eeeeeeee.[‌888‌] Meeeeeeeeeeee ee eeee eeeeeeeeeee ee eee eee ee eeeeeeeee eeee eee eeeee ee Meeee eeeee ee eeeeeeeeee eee eeeeeeee eeeeeeeee, ee eeeee eee eeeeeeeeeee ee eeeeeeeeeeeeeee eeee eee eeee eeeeeeeeeeeee. Meee eeeeee ee eee eee ee eeeeeeee eeeeeee eeee eeeeeee eee-eeeeeeeeeee 888 (M=Me, M) eeee eee eeeee eeee/eeeeeeee eeeeeee 888 eee eeee eeee eee eeeeeeee/eeeeeeee eeeeeee 888. Mee eeeeeeeee ee e eeeeeeee eeeeeeeee-eeeeeeeeee eeeeeeee eeeeeee 888 ee eeee eeeeeeee, eeeeeeeeeeee ee eee eeeeeeee ee eeeeeee eeee ee M,M,M,M-eeeeeeeeeeeeeeeeeeeeeeeeee (MMMMM). Meeeeeee eee eeeeee eeeeeeeeeeeee eeeeeeee ee eeee ee eee eeeeeee eeeeeeeeeeeee eeeeeeeeee eee eee eeee eeeeeee, eeeeeee ee eeeee ee eeee eeeeee eeeeeee eee eeeeee ee eeeeeeeeeee.

Meeeee 88 Meeeeeeee ee eee-Meeeeeeeee Meeeeeee Meeeeeeee Meee[‌888‌‌888‌]

Mee eeeeeee eee-eeeeeeeeee eeeeeeeeeeeee eeee eee eeeeeeeeeeeee eee eeeee eeeeeeeee ee eeee eeee eeeeeeeeeeeeee eee eeeeeeeee eeeeee. (Meeee 88).[‌888‌‌888‌] Mee eeeeeee, eee Meeeee eeeeeee 888[‌888‌] ee eeeeeeee ee eee eee ee e eeeeeeee eeeeee eee ee eeeeeeee ee eeeeeeeeeee eeee e Meeee eeee ee eeeeeee eeeeeeeeee (Meeee 88, eeeeeee 88).[‌888‌,‌888‌] Mee eee ee eeeeeeeeeeeeee eeee eeee eee eeeeeeee(MM) eeeeeeee ee eeeeeeeeeeeeeee ee e eeeeee eeeeeeeee eee eee eeeeeeeeeeeee ee eeeeeeeee eee eeeeeee (eeeee 8).[‌888‌,‌888‌] Me eeeeeeee eeeeeeeee eeeeeeeee e eeeeee eeeeeee eeeeeeee eeee eee eee eeeee-eeeeeeeee eeeeee (eee Meeeeeee eeeeeee) ee eeee eeeeeeeee (eeeee 8).[‌888‌] Mee eee ee eeee(MM) eeeeeeee ee e eeeeeeee eee eeee eeeeeee eee eeeeee ee eeee eeeeeeee, eee, ee eeeeeeeeeee eeee M,M,M,M-eeeeeeeeeeeeeeeeeeeeeeeeee (eee MeeeeMeeeeee eeeeeee), ee eeeeeeee eee eee eeeeeeeeeeeee ee eeeeee (eeeee 8).[‌888‌,‌888‌]

Meeee 88 Meeeeeee eee Meeeeeeeee eee eee Meeeeeeeeeeee ee Meeeeeee Meeeeeeee eeee eee-Meeeeeeeee Meeeeee[‌888‌‌888‌]

Meeee eee-Meeeeeeeee Meeeeee Meeeeeee eee Meeeeeeeee Mee
8 Me(MM8MeMe)8MMM Me(MM8MeMe)8MMM (888), MeMe8 [‌888‌,‌888‌]
8 Me(MM8MeMe)8MMM Me(MM8MeMe)8MMM (888), β-MeMe8, MMM [‌888‌]
8 Me(MM8MeMe)8MMM Me(MM8MeMe)8MMM (888), MM8MMe8, MMM [‌888‌]
8 MeMeMM8MeMee MM8Me8, Me, MeMe8, MMM [‌888‌,‌888‌]
8 MeMeMM8MeMee MM8Me8, Me, MeMe8, MMM, 88 ee 8°M, 8e [‌888‌,‌888‌]
8 MeMeMM8MeMeeMMMMM MM8Me8, Me, MeMe8 (eee.), MeMe8, MMMMM, MMM, 88°M [‌888‌,‌888‌,‌888‌]
8 MMeMM8MeMee MM8M8, Me, Me8Me, MMM, eeeeee [‌888‌,‌888‌,‌888‌]
8 MMeMM8Me(MeMe)e MM8M8, Me, Me(MeMe)8, MMM [‌888‌]
8 MMeMM8MeMee MM8M8, Me, MeMe8, MMM [‌888‌,‌888‌,‌888‌]
88 MM8(MeM)8 MM8M8, Me, eeeeeeeeee, MMM [‌888‌]
88 MM8(MeM)8 MM8M8, Me, MeMe8 (eee.), MMM [‌888‌,‌888‌‌888‌]
88 MM8(MeM)8 MM8(MeM)8, β-MeMe8, MMM [‌888‌,‌888‌]
88 MMeMM8Me(Me)8Me MM8M8, Me, MMM, 88°M, eeee Me(Me)8Me8 (88) [‌888‌]
88 MeMeMM8Me(Me)8Me MM8Me8, Me, Me(Me)8Me8, MMM, ee [‌888‌]
88 MM8(MeM)8 MM8M8, Me, Me8M [‌888‌]
88 MM8Me8, Me/Me, Me8M, eeee Me(Me)8Me8 (88) [‌888‌]
88 MM8Me8, Me, MeMe8, MMM [‌888‌,‌888‌]

Mee eee-eeeeeeeeee eeeeeee eeeeeeee eeee eeeeeeeeeeeee eee eeeeeeeee eeee [eeeeeeee 888 (M=M); eee Meeeee 88] eee ee eeee eee eee eeeeeeeeeeeee ee eeeeeeee eeeeeeeee eeeee e eeeeeee ee eeeeeeeeee, eeeeeeeee eeee eeee eee eee ee eeeeeeeee eeee ee eeeeeeeeeeeeeeeee (Meeee 88, eeeee 8)[‌888‌,‌888‌] eee eeeeeeee(MM) eeeeeeeeeeee (eeeee 8).[‌888‌] Mee eeeeeeeeeee ee eeeeeeeeeeeee, eeee, eee eeeeeeee(MM) eeeeeeee (eee MeeeeMeeeee eeeeeee) ee eeeeee eee eee eeeeeeeeeeeee ee eeeeeeeee eee eeeeeee (eeeee 8).[‌888‌,‌888‌,‌888‌] Mee eee-eeeeeeeeee eeeeeee eeeeeeee eeee eeeeeeeeeeeee/eeee ee eeee eeeeeeeee eee eee eeeeee eeeeeeeeeeeee ee eeeeeee eeeeeeee eeeeeeeee eeeee eeeeeeeeee eeee eeeeeeeeee eee eeeeeeeee (eeeeeee 88,[‌888‌] 88,[‌888‌‌888‌] eee 88[‌888‌]). Mee eeeeeeee ee eeee eeeeeee eeee eeeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeee(MM) (88) (eeeee 88)[‌888‌] eee eee eeeeeee eeeeeeee eeee eeeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeeee(MM) (eeeeeeeeeee eeeeeeeeee), eeeeeeeeeeeeee, eee eeee (eeeee 88)[‌888‌] eeee eeeeeeee eeeeee eeeeeeeeeeeee eeeeeee. Mee eeeeeeeeeeeee ee eeeeeeeee eee eeeeeee eeeee eee-eeeeeeeeee eeeeeeee eeeeeeeee eeeeeeeee ee eeee eeeeeeee (eeeeeee 88,[‌888‌] 88,[‌888‌] eee 88[888,888). Meeeeeeee eeeeeeeeeeeee ee eeeeeeeee ee eee eeeeeeee ee eeeeeee ee eeeeeeee eeee eee eee ee eee Meeeee eeeeeee 888 eee eeeee eeeeeeeeeeeeeeeeee eeeee eeeeeee (eeeee 8),[‌888‌] eee eeee eee eee ee eeeeeeeeeeeee/eeee ee eeeeeeeeeee eeee eeeeeeeeeeeeeeeee (eeeee 8)[‌888‌,‌888‌] ee eeeeeeee(MM) eeeeeeeeeeee (eeeee 8).[‌888‌]