Lewis-Acid-Catalysed Reaction of 3-Hydroxy-2-oxindoles with Terminal Alkynes: Synthetic Approaches to the Pyrroloindoline Alkaloids
作者:Lakshmana K. Kinthada、K. Naresh Babu、Dikshaa Padhi、Alakesh Bisai
DOI:10.1002/ejoc.201700507
日期:2017.6.8
quaternary centre. On further extension of this method, a variety of spiro-2-oxindoles have been synthesized in high yields. The aforementioned methodology has been used in addressing the cyclotryptamine alkaloids linked with aryl group at the pseudobenzylic position.
An efficient Stork-Danheiser sequence has been developed for the preparation of a variety of 3-alkynyl-2-(hydroxymethyl)cyclohex-2-en-1-ones in good to excellent yields from the corresponding 4,6,7,8-tetrahydro-5H-1,3-benzodioxin-5-ones and terminal alkynes. Several of the 3-alkynyl-2-(hydroxymethyl) cyclohex-2-en-1-one products were catalytically cyclized to give the corresponding 3-aryl-1,5,6,7-tetrahydro-8H-isochromen-8-ones.