An organocatalytic Cloke–Wilson rearrangement of cyclopropyl ketones to 2,3-dihydrofurans is exploited utilizing the homoconjugate addition process. With 1,4-diazabicyclo[2.2.2]octane as the catalyst, the rearrangement in DMSO at 120 °C proceeded in generally high yields, exclusive regioselectivity, and a broad substrate scope. An examination of the mechanism including stereochemical analysis and intermediate
Cycloheptenones are widespread in natural products and bioactive molecules. An efficient and convenient NaH-mediated CopeRearrangement of doubly activated vinylcyclopropanes is reported for the synthesis of cyclohepten-4-ones. These flexible intramolecular reactions were applicable to a wide range of substrates and could be performed on gram scale. The derivatization of the product leads to short
环庚烯酮广泛存在于天然产物和生物活性分子中。据报道,一种高效且方便的 NaH 介导的双活化乙烯基环丙烷 Cope 重排用于环庚烯-4-酮的合成。这些灵活的分子内反应适用于多种底物,并且可以在克规模上进行。产品的衍生化可以快速高效地合成一些有用的功能分子。
Dihydrofuran derivates useful as aroma chemicals, and process for their preparation
申请人:QUANTUM CHEMICAL CORPORATION (a Virginia corp.)
公开号:EP0128584A1
公开(公告)日:1984-12-19
2,4,5-trisubstituted-2,3-dihydrofurans useful as fragrance compounds are provided herein. The compounds of this invention correspond to the general formula
wherein R is an ethyl or vinyl group, R2 is an alkyl group having from 1 to 4 carbon atoms and R1 is a hydrocarbon radical having from 3 to 10 carbon atoms. The 2,3-dihydrofuran compounds of the present invention are useful components in the preparation and formulation of fragranced cosmetic and toiletry products.