title: 5- And 6-exocyclic products, cis-2,3,5-trisubstituted tetrahydrofurans, and cis-2,3,6-trisubstituted tetrahydropyrans via Prins-type cyclization.
abstract: Exocyclic products having cis-2,5 and cis-2,6 substitution were synthesized from terminally substituted alkynyl alcohols with various aldehydes via Prins-type cyclization in good yields. It is of interest that synthesized 5- and 6-exocyclic vinyl cations generated as a result of Prins-type cyclization could be trapped as a vinyl triflate in CH2Cl2 to give 3-furanylidenes and 3-pyranylidenes. Those 3-furanylidenes and 3-pyranylidenes underwent hydrolysis to give the corresponding 3-acyl-substituted products having all-cis-configured isomers, such as 2,3,5-trisubstituted tetrahydrofurans and 2,3,6-trisubstituted tetrahydropyrans.
authors.affiliation: Center for Chemoinformatics Research, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea.
authors.forename: Satish N
authors.initials: SN
authors.lastname: Chavre
authors.forename: Hyunah
authors.initials: H
authors.lastname: Choo
authors.forename: Jae Kyun
authors.initials: JK
authors.lastname: Lee
authors.forename: Ae Nim
authors.initials: AN
authors.lastname: Pae
authors.forename: Youseung
authors.initials: Y
authors.lastname: Kim
authors.forename: Yong Seo
authors.initials: YS
authors.lastname: Cho