ALCOHOLS AND ALKYL HALIDES 75 (i) Hydroxyl controls the numbering because the compound is named as an alcohol. 4.23 Primary alcohols are alcohols in which the hydroxyl group is attached to a carbon atom which has one alkyl substituent and two hydrogens. Four primary alcohols have the molecular formula CsHnO. The functional class name for each compound is given in parentheses CH CHCH CHCHOH CH CH, CHCH,OH CH3 I-Pentanol Methyl-l-butanol Pentyl alcohol) CH, CHCH,CHOH CH3CCH,OH 3-Methyl-1-butanol 2. 2-Dimethyl-1-propanol 3-Methylbutyl alcohol) (2, 2-Dimethylpropyl alcohol) Secondary alcohols are alcohols in which the hydroxyl group is attached to a carbon atom which has two alkyl substituents and one hydrogen. There are three secondary alcohols of molecular formula C-H-O CH3CHCH, CH,CH3 CH, CH, CHCH, CH3 CH CHCHCH ethylbutyl alcohol) (-Ethyipropyl alcohol) (1.2-Dimethylpropyl alcohol) Only 2-methyl-2-butanol is a tertiary alcohol(three alkyl substituents on the hydroxyl-bearing OH CH3 CCH, CH3 H3 (1. 1-Dimethylpropyl alcohol) 4.24 The first methylcyclohexanol to be considered is 1-methylcyclohexanol. The preferred chair confor mation will have the larger methyl group in an equatorial orientation, whereas the smaller hydroxyl oup will be axial Most stable conformation of I-methylcyclohexanol Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website(i) Hydroxyl controls the numbering because the compound is named as an alcohol. 4.23 Primary alcohols are alcohols in which the hydroxyl group is attached to a carbon atom which has one alkyl substituent and two hydrogens. Four primary alcohols have the molecular formula C5H12O. The functional class name for each compound is given in parentheses. Secondary alcohols are alcohols in which the hydroxyl group is attached to a carbon atom which has two alkyl substituents and one hydrogen. There are three secondary alcohols of molecular formula C5H12O: Only 2-methyl-2-butanol is a tertiary alcohol (three alkyl substituents on the hydroxyl-bearing carbon): 4.24 The first methylcyclohexanol to be considered is 1-methylcyclohexanol. The preferred chair confor￾mation will have the larger methyl group in an equatorial orientation, whereas the smaller hydroxyl group will be axial. OH CH3 Most stable conformation of 1-methylcyclohexanol CH3 OH CH3CCH2CH3 2-Methyl-2-butanol (1,1-Dimethylpropyl alcohol) OH CH3CHCH2CH2CH3 2-Pentanol (1-Methylbutyl alcohol) OH CH3CH2CHCH2CH3 3-Pentanol (1-Ethylpropyl alcohol) CH3 OH CH3CHCHCH3 3-Methyl-2-butanol (1,2-Dimethylpropyl alcohol) CH3 CH3CH2CHCH2OH 2-Methyl-1-butanol (2-Methylbutyl alcohol) CH3 CH3CHCH2CH2OH 3-Methyl-1-butanol (3-Methylbutyl alcohol) CH3 CH3 CH3CCH2OH 2,2-Dimethyl-1-propanol (2,2-Dimethylpropyl alcohol) CH3CH2CH2CH2CH2OH 1-Pentanol (Pentyl alcohol) 4,5-Dimethyl-2-hexanol 6 5 4 3 2 1 OH ALCOHOLS AND ALKYL HALIDES 75 Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website