Hexane → 2,2-Ethylenedioxy-6-formyl-10-methyl-5,9-undecadiene

Participants

Reaction Conditions

Reaction Steps

In 160 ml of anhydrous tetrahydrofuran was suspended 38.5 g of 4,4-ethylenedioxypentan-1-yltriphenylphosphonium bromide, and to this was added the equimolar amount of a n-butyl-lithium-hexane solution at -20° C in a stream of nitrogen. The reaction mixture was stirred for 1 hour and cooled to -60° C. To this was added 14.5 g of 1,1-diethoxy-6-methyl-5-hepten-2-one, and the resulting mixture was stirred at room temperature for 3 hours. The reaction mixture was, after addition of ice-water, extracted with n-hexane and from the extract was obtained an oil. The oil was suspended in 250 ml of 50 % acetic acid and stirred at room temperature for one hour. 2,2-Ethylenedioxy-6-formyl-10-methyl-5,9-undecadiene obtained by the n-hexane extraction, not purified, was reduced in 100 ml of ethanol by using 500 mg of sodium borohydride. The product thus obtained was chromatographed on the silica gel (100 g) column to yield 7.3 g of 2,2-ethylenedioxy-6-hydroxymethyl-10-methyl-5,9-undecadien.

Provenance & Evidence