Science of Synthesis

Oishi, M., Science of Synthesis, (2004) 7, 292.

Cyclopropane ring formation from alkenes, especially the Simmons–Smith reaction using zinc reagents, is well investigated. The occurrence of small rings in natural products and the hydrocarbon functionality for ring expansions and chain elaborations makes the transformation useful. Organoaluminum-promoted cyclopropanation was reported earlier by Hoberg and Miller.[‌154‌,‌248‌,‌249‌] Operational and chemical yield improvements were described by Yamamoto and co-workers. Their procedure involves the treatment of alkenes with readily available triorganoaluminum compounds and alkylidene iodides under mild conditions for several hours, giving cyclopropranation products in good to excellent yields between 73–99% (‌Scheme 59‌).[‌250‌,‌251‌] After optimizing solvents and the quantity of trialkylaluminum compounds, cyclopropanes were obtained from a variety of alkenes including terminal, internal, monocyclic and bicyclic alkenes, a silyl enol ether, and allylic silanes,[‌252‌] but allylic alcohols with a large trialkylsilyl group at the γ-position give homoallylic iodides.[‌253‌] Notably, the chemoselectivity in the cyclopropanation of terpenes, geraniol, and perillyl alcohols (e.g., to give ‌31‌) appears to be complementary to that observed with the Simmons–Smith reagent but less selective than with samarium reagents.[‌254‌,‌255‌]

‌Meeeee 88‌ Meeeeeeeeeeeeeee–Meeeeeeeeeeee-Meeeeeee Meeeeeeeeeeeeeee ee Meeeeee[‌888‌,‌888‌]

Meeeeee eeeee ee eee eeeeeeee eeeeee eeeeee eeeeeeeeeeeee eeeee ee eeeeeeeee ee eeeeeeee eee eee eeeeee eeeee eeeeeeee eeee eee eeeeeeeeeeeeeeeee eeeeeeee eee eeeeeeee eeeeeeeeeeee ee eeee eeeeeeeeee eee eeeeeeeeee eeeeeeeeee.[‌888‌] Meeeeeeeeeeeeeee ee ee eeeeee eee eeeeeeeeeeeeeeeeeeeee eee eee eeeeeeeeee eeeeeeeee ee ee eeeeeeeee eee eeeeee eeeee eeee-MeM eeeeeeeeeeeee (MMMM) eeeeeee, eeeeeeeeeeeeeeeeee eeee (MMM, ‌88‌), eee eeeeeeee (‌Meeeee 88‌).[‌888‌] Meeeeeee ee eeeeeeeee eee Meeeeee–Meeee eeeeeee eeee e eeeeee ee eeeeeeee. Me eee eeeee eeee, eeeeeeeeeeeeeeeee eee eeeeeeeeeeeee eeeeee eeeeeeeeeeee eeee eeeeee ee eee eeee eeeeeeeeeee ee eee eeeeee ee eeee ee ee eee eeeeeeeeeeeeeeeeeeeee, eee eee eeeeeeeeeeeee eeeeeeeeeeeeeeeee eeee eee eeeeee ee eeee eeeee; eeeeeeeeee eeeeeeeee eeeee 8,8,8,8-eeeeeeeeeeeeeeeeeeee-8-eeee (MMMMM) eeee ‌88‌.

‌Meeeee 88‌ Meeeeeeee Meeeeeeee ee eee MMMM Meeeee Meeeeeeee Meeeeeeeeeeeeeeeee Meee[‌888‌]

Me e eeee eeeeeee, 8,8-eeeeeeeeeeeee eeeeeeeeeeeeeeee eeeeeeee eeee eeeeeeee eeee eee­eeeeeeeeeeeee, eeeeeeee eeeeeee, eee eeeee eeeeeeee ee eeeeeeeeee-eeeee eeeeeeeee eeeeeee eeeeeeeee-eeeeeeeee eeeeeeeeeeeeeeeeeee eeeeeeeee eee eeeeeeeeee eeeeee-eeeeeeeee eeeeeeee (‌Meeeee 88‌).[‌888‌,‌888‌] Mee eeeeeeeee ee eeee eeeeeeee ee eeeee eeeeeee. Me eee eeeee eeee, eee eeeeeee eeeeeeeee-eeeeeeeee eeeeeeeee ee eeeeeee eeee eeeeeeeeeeeeeeee eeeeeeee ee eeeeeeee eeee eeeeeeeeeeeee eeeeeee ee eeeeeeee eeeeeee eeeeeee ee eeeeeeeeeee ee ‌Meeeee 88‌.[‌888‌,‌888‌] Mee eeeeeee eee eeee eeeeeee 8,8-eeeeeeeeeeeee eeeeeeeeeeeee.

‌Meeeee 88‌ Meeeeeeeeeeeeeee Meeeeeeee ee Meeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeeee(MM) eee Mee(eeeeeeeeeeeeeee)eeeeee(MM)[‌888‌,‌888‌]

‌Meeeee 88‌ Meeeeeeeeeeeeeee ee Meeeeee ee Meeeeeeeeee(η8-eeeeeeeeeeeeeeee)eeeeeeeee(MM)[‌888‌,‌888‌]

Meeeeeeeeeee Meeeeeeee

[(8M)-8-(8-Meeeeeeeeeeeeeeee)eeeeeeee-8-ee-8-ee]eeeeeeee (‌88‌); Meeeeee Meeeeeeee:[‌888‌]

M eee, 8 M, eeeee-eeeeee, eeeee-eeeeeeee eeeee eee eeeeeeee eeee e eee eeeee, e 88-eM eeeeeeee-eeeeeeeeee eeeeeeee eeeeee, e eeeeee eeeeee, eee e Meeeee-eeeeee eeeeeeee eeeeeeee eee. Mee eeeee eee eeeeeee eeee eeeee, eeeee eeeee (M)-(–)-eeeeeeee eeeeeee (88.88 e, 88 eeee) eeeeeeee ee MM8Me8 (888 eM) eee eeeeeeee eeeeeee eee eeeeee eeee eee eeeee. Mee eeee eee eeeeeee eee eMe8Me (88.8 eM, 888 eeee) eee eeeee eeee eee eeeeeeee eeeeee eeee 88 eee ee ee. Meeee eee eeeeeee eee eeeeeee ee ee eee 88 eee, MM8M8 (8.8 eM, 88 eeee) eee eeeee eeeeeeee eeee e eeeeeee eeee 88 eee. Mee eeeeeee eee eeeeeee ee ee eee 8 e, eee eeeeee eeee eee-eeee ee MeMM (8%, 888 eM). Mee eeeeeee eeeee eee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeeeeee eeee MM8Me8 (8 × 888 eM). Mee eeeeeeee eeeeeeee eeee eeeee (Me8MM8), eee eeeeeeeeeeee eeee e eeeeee eeeeeeeeee ee ee. 88 Meee. Mee eeeeeeee eee eee eeeeeeeee eeeee eeeeeee eeeeeeee ee eeee eee eeeeeee ee e eeeeeeeee eeeeee; eeeee: 88.88–88.8 e (88–88%); ee 888–888°M/88 Meee.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 88/8, 888.
• 8.Meeeee-Meee, (8888) M 88e, 888.