Synthesis
Rosefuran was synthesized in 1968 by George Büchi via the organomercury compound bis(3-methyl-2-furyl)mercury. Rosefuran has been synthesized in many steps from common starting materials starting with prenyl chloride (3-methyl-but-2-en-1-yl chloride). Rosefuran has also been synthesized via cyclization of suitable acyclic precursors, such as, 5-oxogeraniol and 5-hydroxycitral (4-hydoxy-3,7-dimethyl-(E)-2,6-octadienol). Rosefuran has also been prepared via palladium catalyzed cross coupling of the methyl ester of 4-bromo-5-methyl-2-furancarboxylic acid followed by decarboxylation. Alternatively, rosefuran has been prepared from other furan derivatives. Thus, Wittig reaction of 3-methyl-2-furanacetaldehyde with triphenylphosphonium isopropylide gave rosefuran in 67% yield. The aldehyde was obtained via Claisen rearrangement of 3-(vinyloxymethyl)furan. Similarly, the readily available 3-bromofuran was reacted with 3,3-dimethylallyl bromide and lithium diisopropylamide in THF solution, followed by reaction at with methyl iodide and N-butyllithium in THF, yielding rosefuran. A patented process for the manufacture of rosefuran via condensation of 3-formylpropionic acid methyl ester with crotonaldehyde has been described. The intermediate ketoaldehyde is cyclized to a furan derivative which is converted to rosefuran in 33% overall yield via Grignard reaction to give 2-methyl-4-(3-methyl-2-furanyl)-2-butanol followed by dehydration.Applications
Rosefuran is a desirable component of rose oil, a natural fragrance material. Rosefuran is the major constituent (58% by weight) of the essential oil of '' Perilla ocimoides'', a herbaceous, annual plant cultivated inReferences
{{DEFAULTSORT:Rosefuran Furans