1559Tch10175-19811/3/0515:33Page187 Solutions to Problems187 ftriplets CH2 groups at=2.4 may be split into four lines- by different size (i)The signal for the CH group at =1.2 will be split into a triplet by the neighboring CH2 group.In the simplest possible situation.the signal for the CH group at=2.0 will be split 1 carbon)he stants to the H- predicts.In reality.the signal for the CH doublets. (The and 8 3.4 will b CHgroupat.0will be split into a quartet by the neighboring CHgroup. 38.Procedures are similar to those of Problem 37.We show each structure below,and near each group of er of lines into w split).by ⊕ CH3(s) CH3(d) (a)CH.CCH.C CH,CHCH CH.Br CH-CI CH3() CH.CHCHOR. CH.CCH.OH e) CHs. CICH.CHCCH Br Br CH3 Br Br CHa 39.In some cases assignments of signals with similar chemical shifts cannot be unambiguously made without further information.such as integration data. 6=5840mm 6 ppm间lines—a “triplet of triplets”—by the combined coupling with two neighboring cis hydrogens and two neighboring trans hydrogens ([2
1 3] [2
1 3] 9). Conversely, the signal for the CH2 groups at  2.4 may be split into four lines—a “doublet of doublets”—by different size coupling with the cis and trans hydrogens on the neighboring CH2 group ([1
1 2] [1
1 2] 4). (i) The signal for the CH3 group at  1.2 will be split into a triplet by the neighboring CH2 group. In the simplest possible situation, the signal for the CH2 group at  2.0 will be split into a quintet by the combined effect of its neighboring CH3 group and the CH group on its other side (on the carbonyl carbon). The signal for the CH group at  9.5 will be split into a triplet O B by its neighboring CH2 group. As we shall see in Chapter 17, coupling constants to the HOCO hydrogen are smaller than usual and lead to more complicated patterns with more lines than the simple N
1 rule predicts. In reality, the signal for the CH2 group will be split into a quartet of doublets. (j) The signals at  0.9 and  3.4 will be singlets (no neighbors). The signal for the CH3 group at  1.4 will be split into a doublet by the neighboring CH group. The signal for the CH group at  4.0 will be split into a quartet by the neighboring CH3 group. 38. Procedures are similar to those of Problem 37. We show each structure below, and near each group of hydrogens, the multiplicity of its signal (in plain English, the number of lines into which it is split), by using one of the following abbreviations: s, singlet; d, doublet; t, triplet; q, quartet; quin, quintet; sex, sextet; sept, septet; oct, octet; and non, nonet. All multiplicities have been determined by applying the N
1 rule. (a) (b) (c) 39. In some cases assignments of signals with similar chemical shifts cannot be unambiguously made without further information, such as integration data. (a) Cl2CHCH2Cl  5.8 4.0 ppm ClCH2C CHCH3, CH3 CH3 Br ClCH2C CHCH3, CH3 CH3 ClCH2CH CCH3, CH3 CH3 Br Br ClCH2CHCCH3 CH3 Br CH3 (s) (sept) (s) (q) (d) (d) (t) (s) (d) (d) (sex) (d) (s) (s) (s) ClCH2CH2CH2CH2OH, CH3CHCH2OH, CH2Cl CH3 Cl CH3CCH2OH (oct) (s) (s) (s) (t) (t) (d) (d) (d) (s) (s) (quin) CH3 Br (s) (d) (quin) (q) (t) (d) (t) (oct) (d) (non) (q) (t) CH3CCH2CH3, CH3 BrCH2CHCH2CH3, CH3 CH3CHCH2CH2Br Solutions to Problems • 187 6 5 4 3 2 ppm (δ) 1559T_ch10_175-198 11/3/05 15:33 Page 187