6-(7-Hydroxyheptyl)-7-(3-hydroxy-4-methyloct-1-enyl)-1,4-dioxaspiro[4,4]nonane → 7-[2-(3-Hydroxy-4-methyloct-1-enyl)-5-oxocyclopentyl]heptanol
Reaction equation
[OH:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH:9]1[CH:17]([CH:18]=[CH:19][CH:20]([OH:27])[CH:21]([CH3:26])[CH2:22][CH2:23][CH2:24][CH3:25])[CH2:16][CH2:15][C:10]21OCC[O:11]2>Cl>[OH:27][CH:20]([CH:21]([CH3:26])[CH2:22][CH2:23][CH2:24][CH3:25])[CH:19]=[CH:18][CH:17]1[CH2:16][CH2:15][C:10](=[O:11])[CH:9]1[CH2:8][CH2:7][CH2:6][CH2:5][CH2:4][CH2:3][CH2:2][OH:1]Participants
3
Conditions
- Temperature
- 60 °C
Procedure
A mixture of crude 6-(7-hydroxyheptyl)-7-(3-hydroxy-4-methyloct-1-enyl)-1,4-dioxaspiro[4,4]nonane (0.5 g.) and hydrochloric acid (50 ml; 2N) was stirred at 60° C. for 2 hours, cooled to ambient temperature and then extracted with diethyl ether. The ether extract was washed with water and dried over magnesium sulphate. Removal of the solvent under reduced pressure gave a crude product (0.4 g.) which was purified by preparative thin layer chromatography on silica gel, using a mixture of diethyl ether, ethyl acetate and hexane (2:1:1 v/v) as eluant, to give 7-[2-(3-hydroxy-4-methyloct-1-enyl)-5-oxocyclopentyl]heptanol (0.15 g.), νmax 3400 cm-1, 1725 cm-1, 970 cm-1 ; Elemental analysis: Found C, 74.8; H, 11.7%; C21H38O3 requires C, 74.5; H, 11.53%; N.M.R. (approximately 10% solution in deuterochloroform): multiplets at 5.7-5.5 δ, 3.98 δ and 1.05-0.7 δ, triplet at 3.6 δ (J = 6 cycles/sec.), based singlet at 2.05 δ.