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Schobert, R.; Hölzel, C.; Barnickel, B., Science of Synthesis, (2010) 47, 69.
Reactive ω-carbonylated ylides must be generated in situ to allow controlled intramolecular self-reaction. For example, the treatment of ω-carbonylphosphonium salts 150 with bases (e.g., alkoxides, triethylamine, butyllithium, sodium hydride, or sodium hexamethyldisilazanide) liberates the corresponding ylides, which undergo rapid intramolecular Wittig alkenation to yield cycloalkenes 151 (Table 7). This approach gives cyclopentenes and cyclohexenes,[25,26] but three- and four-membered ring products are not accessible in this way. Bridgehead bicycloalkenes can be built up by the annulation of cycloalkanones with an ylidic side arm tethered to the α-[485–487] or β-[488,489] position. Medium-sized ring products are also obtained by this method in moderate yields[33] as is a bridged formal E-cycloheptene.[490] Further examples are given in Table 7.
Meeee 8 Meeeeeeeeeee eeee Meeeeeee-Meeeeeeeeee Meeeeeeeeee Meeee eee Meeee[88,888,888,888]
| Meeee | Meeeeeeeeee Meee | Meeeeeeeee | Meeeeee | Meeee (%) | Mee |
|---|---|---|---|---|---|
| 8 |  |
MeM(M)MM8Me, MMMM, 88°M, 88 eee | |
88 | [888] |
| 8 | |
MeM (8 eeeee), eeeeeeeeee, Me8M(MM)Me, 88°M, 88 eee | |
88 | [888] |
| 8 | |
e-MeMM, eeeeeee, 88°M, 8 e | |
88e | [888] |
| 8 | |
MeM, MMM, 888°M, 8 e | |
88 | [88] |
e Meee 8α-eeeeee eeeeee.
Meeeeeeeeeee Meeeeeeee
8,8,8e,8,8,8-Meeeeeeee-8M-eeeeee (Meeee 8, Meeee 8); Meeeeee Meeeeeeee:[888]
[8-(8-Meeeeeeeeeeeee)eeeee]eeeeeeeeeeeeeeeeeeee eeeeeee (88.8 e, 88.8 eeee), eeeee eee eeeeeeee ee e eeeee-eeee eeeee ee 88% eeeee ee eeeeeee eee eeeeeeeeeeeee eee eeeeeee eeee Me8M (8 eeeee) ee eeeee Me8M ee 888°M eee 88 e ee e eeeeee Meeee eeeeeeee eeee, eee eeeeeeeee ee MMMM (88 eM). Mee eeee eee eeeee eeeeeeee ee e eeeeeee eeee ee MeM(M)MM8Me (ee. 88 eeee) ee MMMM (88 eM) eeeee M8. Mee eee eeeeeeeeee eee eeeeee ee 88°M eee 88 eee, eeee e eeeee eeee eee eeeeeeee. Mee eeeeeee eeeeee eee eeeeeeeee ee 88–88°M/88 Meee eeee e eeee eeee, eeeeeee eeee eeeeeee, eeeeee eeee M8M, eee eeeee (MeMM8). Meeeeeeeeeeeee eeee eee eeeeeee; eeeee: 8.88 e (88%); ee 888–888°M.
References
| [25] | Meeeee, M. M.; Meeeee, M. M., M. Mee. Meee., (8888) 88, 888. |
| [26] | Meeeeee, M. M.; Meeeeeeee, M., M. Mee. Meee., (8888) 88, 8888. |
| [33] | Meeee, M.; Meeeee, M.; Meeeee, M.; Meeeeee, M., M. Mee. Meee., (8888) 88, 888. |
| [482] | Meeeee, M. M., Meee. Meee. Meee, (8888) 88, 88. |
| [485] | Meeeee, M. M., Meeeeeeeeee Meee., (8888), 8888. |
| [486] | Meeeee, M.; Meeeee, M., Meeeeeeeeee, (8888) 88, 8888. |
| [487] | Meeee-Meeeeeeeee, M. M.; Meeee, M. M., Meee. Meee. Meee. Meee-Mee, (8888) 888, 888. |
| [488] | Mee, M.-M.; Meeeee, M.; Meeee, M., Meeeee, (8888) 88, 88. |
| [489] | Meeeee, M. M.; Meeeeeeee, M., M. Me. Meee. Mee., (8888) 88, 8888. |
| [490] | Meeeee, M. M.; Meeeeeee, M. M., Meee. Meee. Meee, (8888) 88, 88. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 88/8, 888.
- 8.Meeeee-Meee, (8888) 88/8, 888.
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