Organic Chemistry

Problems 835

Describe how each of the following compounds could be prepared, using a Reformatsky reaction:

a. c.

b. d.

53. The ketone whose spectrum is shown here was obtained as the product of an acetoacetic ester synthesis. What alkyl
    halide was used in the synthesis?


54. Indicate how the following compounds could be synthesized from cyclohexanone and any other necessary reagents:

a. c. e.

b. d. f.

55. Compound A with molecular formula has two peaks in its spectrum, both of which are singlets (with ratio ).
    Compound A reacts with an acidic aqueous solution containing mercuric sulfate to form compound B that gives a positive
    iodoform test (Section 19.4) and that has an^1 H NMRspectrum that shows two singlets (with ratio 3:1). Identify A and B.

C 6 H 10 1 H NMR 9:1

O

O

COCH 2 CH 3

O O

CCH 2 CH 2 CH 3

(two ways)

O

O

CH

O O

CH 2 CH 2 CCH 3

O O

CH 2 CH 2 CH 2 CH 3

10 9 8765 4 3210

(ppm)

frequency

(^1) H NMR
CH 3 CH 2 CCH 2 COCH 3
OH
CH 2 CH 3
O
CH 3 CH 2 CHCHCOH
OH
CH 2 CH 3
O
CH 3 CH 2 CH CCOH
CH 3
O
CH 3 CH 2 CH 2 CHCH 2 COCH 3
OH O
CH 3 CH 2 CH +
O
CH 3 CHCOCH 3
ZnBr
an organozinc
reagent
a -hydroxy ester
O
CH 3 CH 2 CHCHCOCH 3
CH 3
H 2 O
O− O
+ZnBr
CH 3 CH 2 CHCHCOCH 3
CH 3
OH O