General, Regiodefined Access to α-Substituted Butenolides through Metal−Halogen Exchange of 3-Bromo-2-silyloxyfurans. Efficient Synthesis of an Anti-inflammatory Gorgonian Lipid
摘要:
A variety of alpha-substituted butenolides were efficiently prepared from 3-bromo-2-triisopropylsilyloxyfuran via lithium-bromine exchange and in situ quench with carbon or heteroatom electrophiles. The inherent flexibility of this methodology is illustrated by a short and efficient synthesis of an anti-inflammatory marine natural product.
Synthesis of Laurencione, a Labile Dihydro-3(2H)-furanone Derivative from the Red Alga Laurencia spectabilis
作者:Norbert De Kimpe、Angelina Georgieva、Marc Boeykens、Laszlo Lazar
DOI:10.1021/jo00121a051
日期:1995.8
The first total synthesis of laurencione, a naturally occurring dihydro-3(2H-furanone derivative isolated from the red alga Laurencia spectabilis, is described. The synthesis is comprised (1) of conversion of gamma-butyrolactone into alpha,alpha-dimethoxy-gamma-butyrolactone, (2) addition of methyllithium across the lactone carbonyl, and (3) acid hydrolysis of the acetal moiety. An alternative synthesis consists of the acid-catalyzed conversion of 3,3-dimethoxy-2-hydroxy-2-methyltetrahydrofuran into laurencione methyl ether and subsequent acid-catalyzed hydrolysis. In addition, a convenient synthesis of the coffee and caramel flavor component 2-methyl-3(2H)-furanone has been developed by acid-catalyzed rearrangement of 2-methoxy-2-methyltetrahydrofuran-3-one.