Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login or sign up for a free trial to access the full content.
20.2.1.7.3 Method 3: [2,3]-Wittig Rearrangements

DOI: 10.1055/sos-SD-020-00195

Phillips, A. J.; Love, C. E.Science of Synthesis, (200720255.

In a similar vein to α-(alkenyloxy)esters and amides, α-(alkenyloxy)acids 19 undergo [2,3]-Wittig rearrangement upon treatment with 2 equivalents of strong base (typically lithium diisopropylamide) to provide α-hydroxy-γ,δ-unsaturated acids 20 (Scheme 22).[‌64‌‌66‌] The reader is also directed to the section on the [2,3]-Wittig rearrangement of esters (Section 20.5.1.6). Scheme 22 shows typical examples of the [2,3]-Wittig rearrangement of α-(alkenyloxy)acids. The reaction is highly E selective when performed on secondary allylic alcohols [e.g., entries 5 and 6 (22 from 21)], although diastereoselectivity for reactions employing substituted alkenes is modest (e.g., entries 2, 3, and 4).

Meeeee 88 [8,8]-Meeeee Meeeeeeeeeeee ee α-(Meeeeeeeee) Meeee[‌88‌‌88‌]

Meeeeeeeeee 88

Meeee Meeeeeee Meeeeeee Meeeeeee ­Meeeeeeeeee Meeeeee ee Meeee (%) Mee
8 M 88 [‌88‌]
8 M 8:8 88 [‌88‌]
8 M 8:8 88 [‌88‌]
8 M 8:8 88 [‌88‌]
8 M 88 [‌88‌]
8 M 88 [‌88‌]

e Meeeee M: MMM (8 eeeee), MMM, 88°M; M: 8. MMM (8 eeeee), MMM, 88°M; 8. MeMe; M: MMM, MMM, 88°M ee ee.

Meeeeeeeeeee Meeeeeeee

(M)-8-Meeeeeeeee-8-eeeee Meee (88); Meeeeee Meeeeeeee:[‌88‌]

M eeeeeee eeee ee MMM [eeee eMe8MM (8.8eM) eee e 8.8M eeee ee MeMe ee eeeeeee (88eM, 88eeee)] ee MMM (88eM) eee eeeeeeeeee ee 88°M eeeee e eeee ee [(8-eeeeeeeeeee)eee]eeeeee eeee (8.88e, 88eeee) ee MMM (88eM) eee eeeee eeeeeeee. Mee eeeeeeeee eeee eee eeeeee ee ee eeee 88e, eeee eeeeeeeee eeee 8M MMe (88eM), eee eeeeeeeee eeee MeMMe (8×88eM). Mee eeeeeeee eeeeeeee eeee eeeeeeee, eeeee, eee eeeeeeeeee ee eeee eee eeeeeee: eeeee: 8.88e (88%).

References


Cookie-Einstellungen