Organic Chemistry

Problems 783

57. A compound gives the following IR spectrum. Upon reaction with sodium borohydride followed by acidification, the product with the
    following spectrum is formed. Identify the compounds.


58. Unlike a phosphonium ylide, which reacts with an aldehyde or ketone to form an alkene, a sulfonium ylide reacts with an aldehyde
    or ketone to form an epoxide. Explain why one ylide forms an alkene, whereas the other forms an epoxide.


59. Indicate how the following compounds could be prepared from the given starting materials:

a. d.

b. e.

c. CH 3 CH 2 CH 2 CH 2 Br CH 3 CH 2 CH 2 CH 2 COH

O

OH NHCH 3

COCH 3

O

CH

O

O N CH 3 CH 3

H

N

H

COCH 3

O

CCH 3

OH

CH 3

CH 3 CH 2 CH + (CH 3 ) 2 SCH 2 CH 3 CH 2 CH

O

CH 2 + CH 3 SCH 3

O

87654 3210

frequency

δ (ppm)

2.5 2.62.72.82.9 3 3.5 4 4.5 5 5.5 6 7 8 9 10 11 12 13 14 15 16

4000 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600

Wavelength (μm)

Wavenumber (cm−^1 )

% Transmittance

(^1) HNMR