1559T.ch25.439-45310/20/055:59 AM Page450 EQA 450.chapter 25 HETEROCYCLES:HETEROATOMS IN CYCLC ORGANI COMPOUNDS Substitution at C8 48.H16+2=18:degrees of unsaturation=5 bonds or rings.NMR:CoHs group is 0aip5田383Sg5 oN uo2子03 os9eeA ote pey H H 2-Phenyloxacyclopropane Conc.aq.HCl causes ring opening to 42 OH OH CoHs-CH-CH2 4836a37 The hydrogens of the CHa group are not equivalent because of the adjacent stereocenter.Substitution at C8: 48. Hsat  16  2  18; degrees of unsaturation   (18 2   8)  5
bonds or rings. NMR: C6H5 group is present, accounting for 4 degrees of unsaturation. No alkene COH signals, so the last degree of unsaturation is probably a ring. So far: C6H5O, 2 C, 3 H, O present, adding up to C8H8O. The three H’s all couple to each other (all three signals are split), so an OOH is unlikely. Therefore, the O is an ether oxygen, giving as the only possible answer Conc. aq. HCl causes ring opening to The hydrogens of the CH2 group are not equivalent because of the adjacent stereocenter. OH CH CH2 OH C6H5 4.2 4.8 3.6 and 3.7 H H C C H O Nonequivalent (one is cis to the phenyl group and the other is trans!) C6H5 2-Phenyloxacyclopropane O CH3 N  O CH3 N  O CH3 N  E H E H E H E H E H O CH3 N  O CH3 N  Better (leave pyridine ring intact) O CH3 8 5 N E 450 • Chapter 25 HETEROCYCLES: HETEROATOMS IN CYCLIC ORGANIC COMPOUNDS 1559T_ch25_439-453 10/20/05 5:59 AM Page 450