Citric Acid → 6-(7-Hydroxyheptyl)-7-(3-hydroxy-4-methyloct-1-enyl)-1,4-dioxaspiro[4,4]nonane

6-(7-Hydroxyheptyl)-7-(4-methyl-3-oxooct-1-enyl)-1,4-dioxaspiro[4,4]nonane [1.0 g; prepared as hereinbefore described in Example 1 (v)] was dissolved in methanol (50 ml.) and added to aqueous sodium citrate solution (130 ml; 2% w/v). To this stirred solution, at -5° to 0° C., solid potassium borohydride (2.24 g.) was added portionwise at such a rate as to avoid undue effervescence and the reaction mixture was maintained at pH 8 by the occasional addition of aqueous citric acid solution (10% w/v). After the final addition of the potassium borohydride the reaction mixture was stirred at -5° to 0° C. and pH 8 for 90 minutes. Acetone (50 ml.) was then added, the solution was saturated with sodium chloride, and extracted with diethyl ether. The combined ether extracts were washed with a saturated solution of sodium chloride in hydrochloric acid (2 N) and saturated sodium chloride solution respectively, then dried over sodium sulphate. Removal of the solvent under reduced pressure gave crude 6-(7-hydroxyheptyl)-7-(3-hydroxy-4-methyloct-1-enyl)-1,4-dioxaspiro[4,4]nonane (0.6 g.), νmax 3400 cm-1, 1040 cm-1 , 970 cm-1, which was used in the next stage without further purification.

1. extractionextracted with diethyl ether
2. washThe combined ether extracts were washed with a saturated solution of sodium chloride in hydrochloric acid (2 N) and saturated sodium chloride solution respectively
3. dry with materialdried over sodium sulphate
4. customRemoval of the solvent under reduced pressure

ORD record

ord-eb39cb9ba732428d99699acc39bf72b9

Source dataset

uspto-grants-1982_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04325967