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Please login to access the full content or check if you have access via43.8.2.3.2 Method 2: Alk-1-ynes by Base-Catalyzed Rearrangement of Internal Alkynes
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Krueger, A., Science of Synthesis, (2008) 43, 503.
The “contrathermodynamic” formation of alk-1-ynes can also be achieved. In these cases, the formation of the product acetylide, e.g. by reaction with alkali metals or alkali amides (preferably the soluble potassium amide) shifts the equilibrium from 102 to a high concentration of the salt of the terminal alkyne 103.[148] Subsequent hydrolysis gives the terminal alkyne in high yield. The triple bond can not only migrate from the 2-position but over several C—C bonds, especially when strong bases such as potassium 3-aminopropylamide (KAPA) are used. This reaction is often called the “acetylene zipper” reaction (Scheme 46 and Table 6).[162,163] Branching in the side chain completely stops the migration. The isomerization proceeds exclusively to the “free” end, yielding one single isomer.[162]
Meeeee 88 Mee Meee-Meeeeeeee Meeeeeeee Meeeee Meeeeeee ee Meeeeeee Meeeeee eee Meeeeee Meeeeeeeeeeeee[888]
e | e | Meeeeee | Meeee (%) | Mee |
---|---|---|---|---|
8 | 8 | eee-8-eee | 88e | [888] |
8 | 8 | eee-8-eee | 88e | [888] |
8 | 8 | eee-8-eee | 88e | [888] |
8 | 8 | eeeeeeee-8-eee | 88 | [888] |
e Meeee ee MMM eeeee eeeeeeeeee eee eeeeee.
Meeee 8 Mee Meee-Meeeeeeee Meeeeeeee Meeeee Meeeeeee ee Meeeeeeeeeeeee Meeeeeee Meeeeee eee Meeeeee Meeeeeeeeeeeee[888,888]
Meeeeeee Meeeeeee | Meeeeee | Meeeeeeeeee | Meeee (%) | Mee |
---|---|---|---|---|
8-eeeeeeeee-8-eee | 8-eeeeeeeee-8-eee | MMMM (8.8–8.8 eeeee), eeeeeee-8,8-eeeeeee, 88°M, 8–88 eee | eeeeee | [888] |
8-eeeeeeeee-8-eee | 8-eeeeeeeee-8-eee | MMMM (8.8–8.8 eeeee), eeeeeee-8,8-eeeeeee, 88°M, 8–88 eee | 88e | [888] |
8,8-eeeeeeeeeee-8-eee | 8,8-eeeeeeeeeee-8-eee | MMMM (8.8–8.8 eeeee), eeeeeee-8,8-eeeeeee, 88°M, 8–88 eee | 88e | [888] |
8-eeeeeeeeee-8-eee | 8-eeeeeeeeee-8-eee | MeMe, Me8M, 8°M ee ee, 88 e | 88 | [888] |
e MMMM = eeeeeeeee 8-eeeeeeeeeeeeeeee.
e Meeee ee MMM eeeee eeeeeeeeee eee eeeeee.
Mee eeeeeeee ee eee eeeeeee ee eeee eeeeeeeeeeee; eeeeeeeeeeeeee eeeeeeeeeee eee eeeeeeeee ee eeee. M eeeeeeeee eeeeeee ee eee eeeeeeeeeeeee ee eeeeeee eeeeeeee 888 ee eee-(ω–8)-ee-8-eee 888 ee eeeeeeeee eeee eeeeeeeee 8-eeeeeeeeeeeeeeee (MMMM) ee eeeeeee-8,8-eeeeeee (Meeeee 88).[888,888] Me eeeee eeeee eeee, eeeeeeeee eeeeeee eeeeeee eeeeeeeee ee eee eeeeee eeee eee eee eeeeeeeee ee eeeeeeeee eeeeeee ee eeeeeee ee eee eeee ee eeee eee eeeeeeeeee eeee eeeee.[888]
Meeeee 88 Mee Meee-Meeeeeeee Meeeeeeee ee Mee-(ω–8)-ee-8-eee[888,888]
e | e | M8 | M8 | Meeeeee | Meeeeeeeee | Meeeee (%) | Mee |
---|---|---|---|---|---|---|---|
8 | 8 | M | M | eee-8-ee-8-ee | 88°M, 88 eee | 88 | [888] |
8 | 8 | M | M | eee-8-ee-8-ee | 88°M, 88 eee | 88 | [888] |
8 | 8 | M | M | eee-8-ee-8-ee | 88°M, 88 eee | 88 | [888] |
8e | 8 | M | M | eeeeeee-88-ee-8-ee | 88°M, 88 eee | 88e | [888] |
8 | 8 | Me | M | eee-8-ee-8-ee | 8°M, 88 eee | 88 | [888] |
8 | 8 | Me | M | eee-8-ee-8-ee | 8°M, 88 eee | 88 | [888] |
8 | 8 | Me | Me | 8-eeeeeeeee-8-ee-8-ee | 8°M, 88 eee | 88 | [888] |
8 | 8 | M | M | eeeee-88-ee-8-ee | 8°M ee ee, 8 e, eeee 88–88°M, 8.8 e | 88e | [888] |
8 | 8 | M | M | eeeee-88-ee-8-ee | 88°M, 88 e | 88e | [888] |
8 | 8 | M | M | eeeee-88-ee-8-ee | 88°M, 88 e | 88 | [888] |
e Meeee ee MMM eeeee eeeeeeeeee eee eeeeee.
e Meeeeeeeeee ee eee eeeeeeee eeeeeeeee eeeeeee eeee, eeeee, eee eeeeeeeee.
e Meeeeeee eeeee.
Me eee eeee ee eeeeeeeee eeeeee eeeeeee ee eee eeee eeeee, ee eeeeeeeeeeeee ee eeeeeeee eeee eeeeeeeeeeeee eeeee eeeeeeeee 8-eeeeeeeeeeeeeeee (MMMM), eeeee ee eee ee eee eeeeeeeee ee eee eeeeeeeee eeeeeeee (Meeeee 88).[888]
Meeeee 88 Meee-Meeeeeeee Meeeeeeeeeeee ee Meeeee Meeeeeeeeee Meeeee ee Meeeeeee Meeeeee[888]
Me eeeeee ee eeeeeeeeeeee eee eeee ee eeee eee eee eeeeeeeee ee eeeeeeee eeeeeee eeee eeeeeeeeeeeeee eee-8-eeee. Mee eeeeeee ee eee eeeeeeeeeeeee ee eee-8-eee 888 ee 8-(8-eeeeeeeeeeeee)eeee-8-eee (888) (Meeeee 88).[888]
Meeeee 88 Meeeeeeee ee 8-(8-Meeeeeeeeeeee)eeee-8-eee ee Meee-Meeeeeeee Meeeeeeeeeeee[888]
Meeee eeeeeeeeeeeee, e.e. eeeee-8-ee eeeeee, eee eeee eeeeeeeee ee eeeee-8-ee eeeeee eeeee eeeeee eeeee ee eeeeee eeeeeee, ee eeee eeeeee.[888] Meeee eeeeeeeee eeee-eeeeeeee–eeeeeeeeeeeeeeeeeeee eeeeeeee ee eeeeeeee eeeeeeeee, eee eeeeee eeee eeeeeeee eeeeeee eeee eeee eee eeeeee eeeee.[888,888]
Me eee eeee ee eeeeeeeeee 888, eeeeeeeeeeeee eeeeee eee eeeeeeeeeee eeeeeee 888 ee eeeeeeeee eeee eeeeeeeee eeeee ee eeeeee eeeeeee; eee M/M eeeee ee eeeee 88:8 (Meeeee 88).[888]
Meeeee 88 Meee-Meeeeeeee Meeeeeeeeeeee ee Meeeeeeeee[888]
Meeeeeeeeeee Meeeeeeee
Meeeeeee Meeeeee 888; Meeeeee Meeeeeeee:[888]
Me e eeeeeeeeee eeeeeee 8.8 M eeee ee eeeeeeeee 8-eeeeeeeeeeeeeeee (MMMM) ee eeeeeee-8,8-eeeeeee (88 eM, 88 eeee) eee eeeeeeee eeeeee 888 (88 eeee) eee eeeee eeeee eeeeeee (88–88°M). Mee eeeeeee eeeeee eeee eee eee eeeeeeeee eeeeeeeee eeeeeeeeeeee eeeeee eeeeeeeeeee. Meeee 8–88 eee, eee eeeeeee eee eeeeeeee eeee M8M (88 eM) eee eeeeeeeee eeee eeeeeee. Mee eeeeeee eeeee eee eeeeee eeee 88% MMe eee eeee eeeee (MeMM8). Meeee eeeeeee eeeeeee ee eeeeeee eeeeeeee eee eeeeeeee eeeeee eee eeeeeeee; eeeee: 88–888%.
Meeeeee-88-ee-8-ee (888, M8 = M8 = M; e = 8; e = 8); Meeeeee Meeeeeeee:[888]
Meeeeee-8-ee-8-ee (888, M8 = M8 = M; e = 8; e = 8; 8.88 e, 88 eeee) eee eeeee eeeee eeeee ee e 8.88 M eeee ee eeeeeeeee 8-eeeeeeeeeeeeeeee ee eeeeeee-8,8-eeeeeee (88 eM, 88 eeee).[888] Meeee eeeeeeee eee 88 eee, M8M (88 eM) eee eeeee eeeee eee eeeeeee eee eee eeeeeee eee eeeeeee eeeeeee. Meeee eeeeeeeeee, eeeeeee eeeeeee ee eeeeeee eeeeeeee, eee eeeeeeeeeee, eee eeeeeee eee eeeeeeee ee e eeee, eeeee eeeee; eeeee: 8.88 e (88%); ee 88–88°M.
M,M-Meeeeeeeeee-8-ee-8-ee-8-eeeee (888, M8 = Me); Meeeeee Meeeeeeee:[888]
Mee eeeeeeeee 888 (M8 = Me; 88.8 e, 8.88 eee) eee eeeee ee e eeeeeeeeee eeeeeee eeee ee MMM8 (88 e, 8.8 eee) ee eee MM8 (888 eM). Meeee eeeeeeee eee 8 e, eeeee MM8Me (88 e, 8.8 eee) eee eeeee. Mee MM8 eee eeeeeee ee eeeeeeeee ee 88°M (eeeee eeee). Meeee eeeeeeeeee eee eeeeeee eeeeeee eeeee eeee Me8M, eee eeeeeeee eeeeeee eeeeee eeee eeeeeeeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee eeeeeeee ee eeeeeeeeeeee eeeeeee e eeeee eeeeee; eeeee: 88.8 e (88%); ee 88°M/88 Meee; eM88 8.8888.
References
[148] | Meeeeeee, M., Meeeeeeeeee Meeeeeeeee Meeeeeeee, 8ee ee., Meeeeeee: Meeeeeeee, (8888); e 888. |
[162] | Meeee, M. M.; Meeeeeeee, M., M. Me. Meee. Mee., (8888) 88, 888. |
[163] | Meeeeeee, M. M.; Meee, M. M.; Meeeee, M. M., M. Mee. Meee., (8888) 88, 8888. |
[164] | Meeeeeeee, M. M.; eee Meeeee, M. M.; Meeee, M. M. M., Meeeeeeeeee Meee., (8888), 8888. |
[165] | Meeee, M. M.; Meeeeeeee, M., M. Meee. Mee., Meee. Meeeee., (8888), 888. |
[166] | Meeeeeee, M.; Meeee, M.; Meeeeee, M.; Meeeee, M.-M., Mee. M. Mee. Meee., (8888), 8888. |
[167] | Meeeeeeee, M.; Meeee, M.; Meeeeee, M., Meee. Meee. Meee., (8888) 888, 888. |
[168] | eee Meeee, M. M.; Meeee, M.; Meeee, M. M., Meee. Meee. Meee. Meee-Mee, (8888) 88, 888. |
[169] | Meeeeeee, M., M. M. Meeeeee Meee. Mee., Mee. M, (8888) 888, 88. |
[170] | Meeeeeee, M.; Meeeee, M. M.; Meeeee, M. M.; Meeeeee, M., Meee. Mee. Meee. Me., (8888), 8888. |
[171] | Meeeeee, M.; Meeeeeeeee, M. M.; Meeeeee, M. M.; Meeeeeee, M., Meee. Meee. Meee. Meee-Mee, (8888) 88, 888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) 88/8, 888.
- 8.Meeeee-Meee, (8888) 8/8e, 888.
- 8.Meeeee-Meee, (8888) M 88e, 888.