Stereoselective Synthesis of 2,3,5-Trisubstituted Tetrahydrofurans by an Allyl Silane Metathesis - Nucleophilic Addition Sequence
作者:John Cassidy、Stephen Marsden、Geoffrey Stemp
DOI:10.1055/s-1997-1062
日期:——
Functionalised cyclic allyl silanes have been prepared by the ring closing metathesis of allyldimethylsilyl ethers of homoallylic alcohols. Treatment of these allyl silanes with aldehydes in the presence of boron trifluoride etherate gives high yields of 2,3,5-substituted tetrahydrofurans. Stereoselectivities are excellent for aldehydes with primary substituents, good for secondary substituents and modest for tertiary substituents.
功能化的环状烯丙基硅烷通过同烯醇的烯丙基二甲基硅醚进行环闭交叉反应制备。将这些烯丙基硅烷与醛在三氟化硼醚合物存在下反应,可以获得高产率的2,3,5-取代四氢呋喃。对于具有初级取代基的醛,其立体选择性优异;对于次级取代基表现良好;而对于三级取代基则适中。