Mercuric chloride and iodide mediated cyclization of tethered alkynedithioacetals as a general route to five- and six-membered rings: tuning of regioselectivity by alkyne substitution.
[reaction: see text] Mercuric chloride mediated cyclization of tethered alkynedithioacetals has been established as a general route to five- and six-membered carbocycles and heterocycles. Substitution at the alkyne terminus leads to preferential formation of five-membered rings, whereas unsubstituted alkynedithioacetals give six-membered rings as the major products. Mercuric iodide interrupts the reaction at the intermediate dithioacetal stage.
Biswas
Goutam
G
Indian Institute of Chemical Biology, Kolkata, India.
Ghorai
Subir
S
Bhattacharjya
Anup
A