Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C - - PowerPoint PPT Presentation

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Dec 24, 2022 91 likes •168 views

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below: IR spectrum A Mass spectrum A Solvolysis of 3-bromo-3-methyl-1-butyne

SLIDE 1

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

IR spectrum A Mass spectrum A

SLIDE 2

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

C stretch

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

CH bend

Mass spectrum A

Clearly label two features on the IR spectrum indicating the functional group class of product A.

SLIDE 3

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

C stretch

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

CH bend

Mass spectrum A M+

Clearly label the molecular ion (M+

)

f the mass spectrum.

SLIDE 4

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

C stretch

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

CH bend

Mass spectrum A M+

The fragment appearing at mass 51 suggests a loss of

what functional group from the molecular ion? 66 - 51 = 15 mass units: C (12) + 3 [H (1)] = CH3 (15)

SLIDE 5

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

C stretch

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

CH bend

Mass spectrum A M+

Provide a structural formula for product A.

SLIDE 6

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

C stretch

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

CH bend

Mass spectrum A M+

Product B has molecular formula C5H8O. Provide a

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

IR spectrum A Mass spectrum A

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

Mass spectrum A

Clearly label two features on the IR spectrum indicating the functional group class of product A.

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

Mass spectrum A M+

)

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

Mass spectrum A M+

what functional group from the molecular ion? 66 - 51 = 15 mass units: C (12) + 3 [H (1)] = CH3 (15)

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

Mass spectrum A M+

Solvolysis of 3-bromo-3-methyl-1-butyne (M.W. 147) in water at 50 C for 12 hours gives two products, A and B. The infrared and mass spectra of product A are shown below:

2100 cm-1 C

3300 cm-1 Csp–H stretch < 3000 cm-1: Csp3–H stretch > 3000 cm-1: ~1600 cm-1 Csp2–Hstretch C=C stretch 910 cm-1 625 cm-1 R2C=CH2 bend RC

Mass spectrum A M+

structural formula for product B