Table 2.1.'H chemical shift ranges for organic compounds Enol-OH Carboxylic acid-OH Phenol-OH D20- Alkanol-OH exchangeable Amide-NH protons Amine-NH Thiol-/Thiophenol-SH Aldehyde-CH Heteroaromatics π-electron deficient -electron rich Aromatics (-)-M-substituted /+月M-substit近uted Alkene-CH (-)-M-substituted (+)-M-substituted Alkyne-CH Acetal-CH R2CH-0-,RCH2-0- R2CH-0- RCH2-O- CH30- CHgN< CH3S- CH3 at C=C or C=X Cyclopropane-CH CH3 bonded to metal ·—61514131211109876543210 General rule:the closer to N(O),the bigger(even bigger)chemical shiftsGeneral rule: the closer to N (O), the bigger (even bigger) chemical shifts