An asymmetric approach to coumarin anticoagulants via hetero-Diels–Alder cycloaddition
摘要:
We have developed a general, two-step protocol for the synthesis of chiral non-racemic coumarin anticoagulants (e.g. warfarin. coumachlor and acenocoumarol). This approach features a one-pot three-component tandem Knoevenagel-hetero-Diels-Alder reaction between in situ generated 3-arylidene-2,4-chromanediones and iso-propenyl ether derived from (-)-menthol. (C) 2001 Elsevier Science Ltd. All rights reserved.
Efficient mercury-free preparation of vinyl and isopropenyl ethers of chiral secondary alcohols and α-hydroxyesters
作者:Gilles Dujardin、Sandrine Rossignol、Eric Brown
DOI:10.1016/0040-4039(95)00087-s
日期:1995.3
acetals 2a-h and 5a-d, readily deriving from the α-chiral alcohols 1a-h and ethyl vinylether or isopropenyl methyl ether, underwent selective elimination of primary alcohol upon treatment with triethylamine and trimethylsilyl trifluoromethanesulfonate, and thus afforded good to high yields of the chiral enol ethers 3a-h and 6a-d, respectively.