Science of Synthesis

Masse, C. E., Science of Synthesis, (2007) 20, 349.

An attractive method for the vicinal dicarboxylation of alkenes makes use of the chemistry of α,α-dichlorocyclobutanones.[‌21‌] These can be assembled from a variety of alkenes via [2+2] cycloaddition with dichloroketene.[‌22‌] Treatment of a series of α,α-dichlorocyclobutanones ‌34‌ with butyllithium affords the corresponding α-chloro enolates (‌Scheme 17‌). Acetylation of the lithium enolates with acetic anhydride provides the intermediate enol acetates ‌35‌, which are oxidized with sodium periodate and ruthenium(IV) oxide to afford the substituted succinic acids ‌36‌. This protocol is completely stereospecific with regard to the substituents of the starting alkenes and provides an average yield of 68% for the dicarboxylation process. Examples of the vicinal dicarboxylates that can be accessed via this method are given in ‌Scheme 17‌.

‌Meeeee 88‌ Meeeeeeee ee Meeeeeee Meeee eeee α,α-Meeeeeeeeeeeeeeeeeeeee[‌88‌]

‌Meeeeeeeeee 88‌

Meeeeeeeeeee Meeeeeeee

8,8-Meeeeeeeeeeee Meeeeeee Meeee ‌88‌; Meeeeee Meeeeeeee:[‌88‌]

Me e eeeeeee eeee ee eee 8,8-eeeeeeeeeeeeeeeeeeeee ‌88‌ (8 eeee) ee eeeee MMM (88 eM) ee −88°M eee eeeee, eeeeeeee, 8.88 M MeMe ee eeeeeee (8.88 eM, 8.8 eeee). Mee eeee eee eeeeeee ee −88°M eee e eeeeee ee 88 eee, eeeeeeee ee eee eeeeeeee ee Me8M (8.8 eM, 88.8 eeee). Meee eeeeeee eee eeeeeee ee eeee ee ee eeee e eeeeee ee 8.8 e. Mee eeeeeeeee eeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eeeeeeee eee eeeeeeeee ee e eeeeeee ee MeMM (8 eM), MMe8 (8 eM) (MMMMMMM: eeeee), eee M8M (88 eM), eee eeeeeeeeeeee eeeeeee eeee MeMM8 (8.8 e, 88.8 eeee) eee MeM8 (888 ee, 8.88 eeee). Mee eeeeeee eee eeeeeee ee ee eee e eeeeee ee 88 e, eeeeeee eeee 88% ee MeMM (88 eM), eee eeeeeee eee 8 e ee eeeeeeeee eee eeeeeeeee eeeeeee. Mee eeeeeee eee eeee eeeeeeeee eeee Me8M eee eee eeeeeee eeeee eee eeeeeeeee ee eM ~8–8 eeeee 88% MMe. Mee eeeeeeeee eeeeeee eeeee eee eeeeeeeee eeee MeMMe eee eeeeee eeee 8% ee Me8M8M8. Mee eeeeeee eeeee eee eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeeeee eee eeeeeee ‌88‌.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 88-8, 8888.