Alkanediols

Examples of a 1,2-diol ( 1,2-ethanediol , above), a 1,3-diol ( 1,3-propanediol , middle) and a 1,4-diol ( 1,4-butanediol , below).

The alkanediols , composed of alkane and diol , form a group of substances that consist of straight or branched hydrocarbon chains that contain exactly two hydroxyl groups at different points . They do not contain any other heteroatoms or multiple bonds .

According to the Erlenmeyer rule, both hydroxyl groups are generally bound to different carbon atoms, since compounds with two hydroxyl groups on one carbon atom generally have a low stability.

Dihydric alcohols (alkanediols)
Number of carbon atoms	Molar mass in g mol −1	Systematic name	Common name	Melting point in ° C	Boiling temperature in ° C	Solubility in g · l −1
2	62.1	Ethane-1,2-diol	Ethylene glycol, 1,2-glycol	−15.6	197.2	∞
3	76	Propane-1,2-diol	Propylene glycol	−68	188	∞
3	76	Propane-1,3-diol	Trimethylene glycol	−32	215	∞
4th	90	Butane-1,2-diol	1,2-butylene glycol	−114	192	∞
4th	90	Butane-1,3-diol	1,3-butylene glycol	<−50	207.5	∞
4th	90	Butane-1,4-diol	Tetramethylene glycol	16	230	∞
4th	90	Butane-2,3-diol	2,3-butylene glycol	34 ( meso )	183 ( meso )	∞
5	104	Pentane-1,2-diol	Pentylene glycol	<−40	206	∞
5	104	Pentane-1,5-diol	Pentamethylene glycol	−16	242	∞
6th	118	Hexane-1,6-diol	Hexamethylene glycol	39-42	253-260	5000
7th	132	Heptane-1,7-diol	Heptamethylene glycol	17-19	259
8th	146	Octane-1,8-diol	Octamethylene glycol	63	274
8th	146	2-ethylhexane-1,3-diol	Ethylhexylene glycol	−40	243
9	160	Nonane-1,9-diol	Nonamethylene glycol	45-47	288	9
10	174	Decane-1,10-diol	Decamethylene glycol	72-75	297	0.7
12	202	Dodecane-1,2-diol	Lauryl glycol	58-60		<0.01