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Petasis, N. A., Science of Synthesis, (2010) 47, 183.
Ketones are excellent substrates for carbonyl methylenation with the Petasis reagent 37. This process often works very well even in transformations that are not very efficient with the Wittig or Tebbe reagents. Several examples of this sort are listed in Table 9,[60,61,63,78–84] including the methylenation of readily enolizable ketones (entries 1–3),[60,61,78]) and enones (entries 4 and 5).[60,79] Ketones are generally methylenated preferentially over esters (entry 6),[60] thioesters (entry 7),[80] or vinylogous esters (entry 8),[63] even though all these carbonyl species can also be methylenated (for an example of methylenation of a vinylogous ester, see entry 9).[81] Methylenation proceeds efficiently in the presence of an unprotected hydroxy group (entry 10),[82] while reaction of (S)-2-[(tert-butyldiphenylsiloxy)methyl]-1-tosylazetidin-3-one gives the expected product (entry 11)[83] even though the Wittig reagent fails completely in this process due to substrate fragmentation. The Petasis reagent 37 is also a very efficient reagent for the methylenation of a piperidinone derivative (entry 12).[84]
Meeee 8 Meeeeeeeeeeee ee Meeeeee[88,88,88,88–88]
| Meeee | Meeeeeee Meeeeeee | Meeeeeeeee | Meeeeee | Meeee (%) | Mee |
|---|---|---|---|---|---|
| 8 |  |
Me(Me)8(Me)8 (88), eeeeeee, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), MMM, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), eeeeeee, MMM, 88°M, 88 e | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), eeeeeee, MMM, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), MMM, 88°M, 88 e | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88; 8 eeeee), eeeeeee, MMM, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), e-MeMM8Me, MMM, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), MMM, 88°M | |
88 | [88] |
| 8 | |
Me(Me)8(Me)8 (88), MMM, 88°M, 88 e | |
88 | [88] |
| 88 | |
Me(Me)8(Me)8 (88), eeeeeee, 888°M, 8 e | |
88 | [88] |
| 88 | |
Me(Me)8(Me)8 (88), eeeeeee, 88°M, 88 e | |
88 | [88] |
| 88 | |
Me(Me)8(Me)8 (88; 8.8 eeeee), MMM, 88°M, 8 e | |
88 | [88] |
Meeeeeeeeeee Meeeeeeee
(8eM,8M,8eM)-8,8-Meeeeeee-8-eeeeeeeee-8-[(eeeeeeeee)eeeeee]eeeeeeeeee-8M-eeeeeeeeee[e][8,8]eeeeeee (Meeee 8, Meeee 8); Meeeeee Meeeeeeee:[88]
M eeee ee eee eeeeee (888 ee, 8.88 eeee) ee eeeeeee (8 eM) eee eeeeeeee eeee e 8 M eeee ee eee Meeeeee eeeeeee 88 ee MMM (8.88 eM, 8.88 eeee) eee eee eeeeeee eee eeeeee ee 88°M eee 88 e eeeee eeeeeeeee eeee eeeee. Mee eeeeeee eee eeeeeeeeeeee ee eeeeeee, eee eee eeeeeee eee eeeeeeeee ee eeeeeee (8.8 eM) eee eeeeeeeee ee eeeeeeeeeeeeeee eeeeeeeeeeee (eeeeee eee, eeeeee/MeMMe 8:8) ee eeeeee e eeeeeeeee eee; eeeee: 88 ee (88%).
(8M,8M)-8-(Meeeeeeeeeeeeee)-8-eeeeeeeee-8-eeeeee-8-eeeeeeeeeeeeeeeeeeee (Meeee 8, Meeee 8); Meeeeee Meeeeeeee[88]
MMMMMMM: Meee eeeeeee ee eeeee ee eeeeeeeeeeee ee eee ee 88 °M, ee eee eeeee eeee eee Meeeeee eeeeeee eeeeeeeee e eeeee, eeeeeeeeee, eeeeeeeeeeeee eeeeeeeeeeeee eeee eeeeeeeee eeeeeee eee, eeeeeeeee ee e eeeee eeeeeeee ee eeeeeeee.
Me e eeeeeee eeee ee Me(Me)8Me8 (88; 888 e, 8.88 eee) ee Me8M (8.8 M) eee eeeee 8.8 M MeMe ee Me8M (888 eM, 8.88 eee) ee eee eeee eeeeeee e eeeeeee eeee 8.88 e ee 8°M. Mee eeeeee-eeeee eeee eee eeeeeee ee eeee ee eeeeeee eeeeeeeeeee. Meeee 8 e, eeee M8M (888 eM) eee eeeee eeeeee ee eee eeeeeee, eee eee eeeeeeeee eeeeeeeeee eee eeeeeeeee eeee Me8M (8 × 888 eM). Mee eeeee (MeMM8) eeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eee eeee, eee eee eeeeee eeeee eee eeeeeeeeeee eeeeeeeee ee MMM (888 eM). Mee eeee ee eee Meeeeee eeeeeee 88 eeee eeeeeeee eee eeeee ee e eeeeeee eeee ee eee eeeeeeeee eeeeee (88.8 e, 8.88 eee) ee MMM (888 eM) eeeeeee e eeeeeee ee eee eeee. Meeee eeeeeee eee eeee eee eeee eeeee eeeeee ee eee eeee eee 88 e, eee eeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeee eee eeeeeeeee ee Me8M (888 eM), eee eeeeee eee (888 eM) eee eeeee eeeeee. Mee eeeee eee eeeeeee ee eeeeeeeeee eee eeeeee eeee Me8M (8.8 M). Mee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eee eee eeeeee eee eeeee eee eeeeeeee eeeee. Mee eeee eeeeee eee eeeeeeeee (ee 888–888°M/8.8 Meee) ee eeee eee eeeeeee ee e eeeeeeeee eeeeee; eeeee: 88.8 e (88%).
References
| [60] | Meeeeee, M. M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |
| [61] | Meeeeee, M. M.; Meeeee, M. M., Meeeeeeeeee Meee., (8888) 88, 8888. |
| [63] | Meeeeee, M. M.; Me, M.-M.; Me, M.-M., Meeeeeeeeee Meee., (8888) 88, 8888. |
| [78] | Meeeeeeee, M.; Meee, M.; Meeeeee, M., Meeeeeeeeee, (8888) 88, 8888. |
| [79] | Meeeee, M.; Meeeeeee, M.; MeMeeee, M.; Meeeee, M.; Meee, M., Meeeeeeeeee, (8888) 88, 8888. |
| [80] | Meeee, M. M., MMM; Meeeee, M. M.; Meeeeeee, M. M.; Meeeee, M.; Meeeeeee, M., Mee. Meee., (8888) 8, 8888. |
| [81] | Meee, M. M.; Meeeeeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
| [82] | Meeeeeee, M.; Meee, M. M.-M.; Meeeee, M. M.; Meeñe, M. M.; Meee, M.; Meeeee, M. M.; Meeee, M. M.; Meeeee, M. M.; Meeeeeeeeee, M.; Meeeeee, M. M.; Meeeeee, M. M.; Meeeeeee, M. M., Meeee. Meee., (8888) 888, 8888; Meeee. Meee. Mee. Me., (8888) 88, 8888. |
| [83] | Meeeeeeee, M. M. M.; Meeeeee, M. M. M., Meeeeeeeeee, (8888) 88, 8888. |
| [84] | Meeee, M.; Meeeeee, M.; Meeee, M. M., Meeeeee, (8888), 8888. |
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