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Please login to access the full content or check if you have access via31.6.2.1.3.4 Variation 4: Cleavage of a Siloxy Group (Si—O Bond Cleavage)
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Low, C. M. R., Science of Synthesis, (2007) 31, 620.
Reaction of aryl silyl ethers 130, principally tert-butyldimethylsiloxy groups, with alkyl halides in the presence of base converts them directly into their alkyl equivalents 131 (Scheme 103).[140–142] Use of both cesium fluoride[141] and lithium hydroxide[140] are claimed to allow selective displacement of the silyl group in the presence of a silylated alkanol, e.g. 130 [R1 = (CH2)2OTBDMS]. However, the selectivity of the cesium fluoride reaction has been questioned.[140]
Meeeee 888 Meeeeeeeee ee Meee Meeee Meeeee eeee Meeee Meee Meeeee[888–888]
| M8 | M8 | M8 | M8M (eeeee) | Meee (eeeee) | Meee (e) | Meeee (%) | Mee |
|---|---|---|---|---|---|---|---|
| MM8Me | M | e-Me | MeMe (8.8) | MeM (8.8) | 88 | 88 | [888] |
| Me | M | e-Me | MeMe (8.8) | MeM (8.8) | 88 | 88 | [888] |
| Me | M | Me | MeMe (8.8) | MeM (8.8) | 88 | 88 | [888] |
| M | 8-Me | e-Me | MeMe (8.8) | MeM (8.8) | 88 | 88 | [888] |
| (MM8)8MMMMMM | M | e-Me | MeMe (8.8) | MeM (8.8) | 88 | 88 | [888] |
| (MM8)8MMMMMM | M | e-Me | MeMe (8.8) | MeMM (8.8) | 8 | 88 | [888] |
| MM8 | 8-MM8MMMMMM | e-Me | M8M=MMMM8M (8.8) | MeMM (8.8) | 8 | 88 | [888] |
 |
M | e-Me | MeMe (8.8) | MeMM (8.8) | 8 | 88 | [888] |
| Me | 8-MM8MMMMMM | e-Me | MeMe (8.8) | MeMM (8.8) | 8.8 | 88e | [888] |
| Me | M | e-Me | MeMe (8.8) | MMMM (8.8) | 88 | 88 | [888] |
| MMMe | M | e-Me | MeM (8.8) | MMMM (8.8) | 88 | 88 | [888] |
| MMe | M | e-Me | MeM (8.8) | MMMM (8.8) | 88 | 88e | [888] |
e Meee eeeeeeee eeee eeeeeeee ee eeeeeeee eeee MeM eee eeee ee eee eeee.
e Meeeeeeeeee ee 88% ee 8-eeeeeeeeeeeee.
Meeeeeeeeeee Meeeeeeee
8-(Meeeeeeee)-8-eeeeeeeeeeee (888, M8 = Me; M8 = M; M8 = Me); Meeeeee Meeeeeeee Meeee Meeeee Meeeeeee ee Meee:[888]
8-Meeee-8-(eeee-eeeeeeeeeeeeeeeeeee)eeeeeee (88.8 ee, 8.888 eeee) eee MeMe (88.8 ee, 8.888 eeee) ee MMM (8 eM) eeee eeeeeeeeeeee eeeee ee e eeee ee MeM (88.8 ee, 8.888 eeee) ee MMM (8 eM) ee ee eeeee eeeee. Mee eeeeeeeee eeeeeee eee eeeeeee eee 88 e ee ee eee eeee eeeeeeee eeee e eeeeeeeee eeeeee (eM 8). Mee eeeeeee eeeee eee eeeeeeeee eeee Me8M (8 × 88 eM) eee eee eeeeeeee eeeeeeee eeee eeeeee eeee eeeee, eeeee (Me8MM8), eeeeeeee, eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeee eeeeeee eee eeeeeeee ee MMM (eeeeee eee); eeeee: 88.8 ee (88%).
eeee-Meeeeeeeeeeeeeeeee-Meeeeeeee Meeee Meee Meeeee 888 (M8 = e-Me); Meeeeee Meeeeeeee Meeee Meeeeee Meeeeeeee ee Meee:[888]
MeMM (8.88 eeee) eee eeeee ee e eeeeeee eeee ee eee eee-MMMMM eeeee (8.88 eeee) ee eeeee MMM (8 eM) eee eee eeeeeee eee eeeeeee ee ee. Meeee eeeeeeeeeee ee eee eeeeeeee eeeeeeee, eee eeeee eeeeee (8.88 eeee) eee eeeee eee eeeeeeee eee eeeeeeeee eeeee eeeeeeeeee ee eee eeeeeeee (ee MMM). Mee eeeeeee eee eeee eeeeeee eeee MeMMe, eeeeee eeee M8M eee eeeee, eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeeee); eeeee: 88–88%.
Meeee Meee Meeeee 888; Meeeeee Meeeeeeee Meeee Meeeeeeeeeeeeeeeee Meeeeeee ee Meee:[888]
MMMMMMM: Meeeeeeeee, eeeeeeeee, ee eeee eeeeeeeeee ee eeeeeeeeeee eee ee eeeee.
M 8 M eeee ee MMMM•8M8M ee MMM (8 eeee) eee eeeee ee e eeeeeee ee eee eeee eeeee eeeee (8 eeee) eee eee eeeeeeeeeee eeeee eeeeee (8 eeee) eee eee eeee eee eeeeeee ee eeeee ee ee eeeeeeeee. Mee eeeeeee eee eeeeee eeeee eeeeee eeee eeeeeeeeee eeeee eeeeeee eeeeeeee. Meee MeM eee eee eeeee eeeeee, eee eeeeeee eee eeeeeeeee ee eeeeeee MeMMe (88 eM) eee eee eeee eee eeeeee ee ee, eeeeeeeee MMMM eeeeeeeeeeee eee eee eee eeeeeee ee eeeeeeeeee. Mee eeeeeee eee eeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee eeeeeeeeeeeeeee (eeeeee eee); eeeee: 88–88%.
References
| [140] | Meeeee, M. M.; Meeeeeee, M., Meeeeee, (8888), 888. |
| [141] | Meeeeee, M.; Meee, M.; Meeeee, M., Meeeeee, (8888), 888. |
| [142] | Meeeeeee, M. M., Meeeeeeee, (8888), 888. |
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