Efficient one-pot synthesis of benzopyranobenzopyrans and naphthopyranobenzopyrans by domino aldol-type reaction/hetero Diels–Alder reaction of resorcinols and naphthols
作者:Yong Rok Lee、Yun Mi Kim、Sung Hong Kim
DOI:10.1016/j.tet.2008.10.101
日期:2009.1
The efficient one-pot synthetic approaches for benzopyranobenzopyrans and naphthopyranobenzopyrans are described. The key strategies involve ethylenediamine diacetate-catalyzed cyclization by domino aldol-type reaction/heteroDiels–Alderreaction of resorcinols and naphthols to benzaldehydes with O-allyl ether groups. These reactions provide a rapid route for the synthesis of novel types of polyheterocycles
A highly diastereo- and enantioselective intramolecular Alder-ene reaction with an alkene as the enophile has been developed by using a chiral N,N′-dioxide/nickel(II) complex as the catalyst. This protocol provides a facileroute towards the synthesis of diverse 3,4-disubstituted chroman, tetrahydroquinoline, piperidine and thiochroman derivatives in high yields with good to excellent diastereo- and