One-Step Synthesis of Furan Rings from α-Isopropylidene Ketones Mediated by Iodine/DMSO: An Approach to Potent Bioactive Terpenes

Abstract

The system I2/dimethyl sulfoxide mediates the one-step transformation of α-isopropylidene ketones into furan rings following a biomimetic approach. This methodology has been used for the synthesis of terpene furans such as mintfurane, curzerene, atractylon, and isoatractylon, all of them possessing interesting biological activities. The synthesis of linderazulene directly from 4,5-epoxygermacrone via a cascade reaction shows the potential of this protocol. Additionally, this compound proved to show significant ixodicidal activity.

Sniffing Out the Sustainable Future: The Renewability Revolution in Fragrance Chemistry**

“…The most prominent material for white florals and booster materials is the ubiquitous Hedione (184,Scheme 22). No matter if racemic or in HC ('high cis') quality, the C 5 -side chain is obtained from pentanal, for which there is no renewable source so far.…”

“…Myraldyl acetate (186), synthesized by Diels-Alder reaction of myrcene (23) with acrolein (67), and subsequent reduction and acetylation, is 66 % renewable and possesses a jasmine, green, fruity smell. In summary, for the floral perfumes, besides Biomuguet (154) and Lilybelle (177) there is without doubt a big need for more non-toxic muguet odorants and, most importantly, for a renewable version of Hedione (184).…”

“…To combine the floralcy in the heart of florientals with the creamy-santal base notes, a little mediatory help by lactonic and balsamic notes is usually welcome. This can for instance be done with Tonkalactone (206) [183,184] or its hydrogenated analogue Koumalactone (207) [185] two high-impact materials both related to wine lactone ( 208), [186,187] and dill ether (209). [188,189] Wine lactone (208) confers to white and red wines a sweet coconut bouquet with woody facets and supposedly is the compound that holds the record for the lowest odor threshold.…”