[Dolphinsiu]

In Chlorohydrin process of propylene,
                                                              Cl
                                                               l
CH3-CH2=CH2 + Cl2 + H2O ---> CH3 - CH2 - CH2
                                                      l
                                                     OH

two side products A and B were obtained with the following spectral data.

Product A: C = 31.9%, H = 5.3%
                M/Z (abundance%) 116 (10.6), 114 (65), 112 (100), 78(16.3), 76(50), 40(20)
                HNMR (CD3Cl) : 3.1(2H,d), 3.0(1H,m), 1.3 (3H,d)

                              Cl
                               l
I predict CH3 - CH2 - CH2
                      l
                     Cl

Product B: C=42.1%, H=7.0%
               M/Z (abundance%) 174 (11.0), 172 (65), 170 (100), 136 (19.5), 134 (60),       
                                           123 (16.2), 121 (50), 98 (10)
               HNMR (CD3Cl) : 4.2(1H,m), 3.0(2H,d), 1.2(3H,d)

I have known that there 3C's, 6H's and 2Cl's and MW = 170
but the remaining M.W = 58 is what? Why is that so?

[Dan]

Be careful, you've got some carbons with a valency of 5.

                                                                       Cl
                                                                        l
CH3-CH2=CH2 + Cl2 + H2O ---> CH3 - CH2 - CH2
                                                               l
                                                              OH


                                Cl
                                 l
I predict CH3 - CH2 - CH2
                        l
                       Cl

I think A is MeCHClCH₂Cl

I think B is

Me-CH-CH₂Cl
     |
     O
     |
Me-CH-CH₂Cl

[Dolphinsiu]

Thank you! It seems you are very good in Chemistry. Do you recommend any books that contains this kind of question that make me practise more?

My school library website is
http://library.polyu.edu.hk/search~/t

[Dan]

I don't know of any books, but past exam questions will probably help you practice.

On the following page, in the past exam papers section, follow the "Part 1B", "Part 1A", and "Part I" links. Most of the general organic chemistry papers have spectroscopy questions.

http://www.chem.ox.ac.uk/teaching/

"Part 1A" is easier than "part 1B" or "part 1"

[Yggdrasil]

Here's a site with good problems for practicing interpretation of spectra:

http://www.chem.ucla.edu/~webspectra/