STEREOS ELECTIVE FREE-RADICAL CYCLOADDITION-MACROCYCLIZATION IN FACILE SYNTHESIS OF TRANS-CYCLOHEXANO-FUSED 12-MEMBERED CROWN THIOETHERS

Authors
TROYANSKY EI ISMAGILOV RF SAMOSHIN VV STRELENKO YA DEMCHUK DV NIKISHIN GI LINDEMAN SV KHRUSTALYOV VN STRUCHKOV YT
Citation
Ei. Troyansky et al., STEREOS ELECTIVE FREE-RADICAL CYCLOADDITION-MACROCYCLIZATION IN FACILE SYNTHESIS OF TRANS-CYCLOHEXANO-FUSED 12-MEMBERED CROWN THIOETHERS, Tetrahedron, 51(42), 1995, pp. 11431-11444
Citations number
53
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
51
Issue
42
Year of publication
1995
Pages
11431 - 11444
Database
ISI
SICI code
0040-4020(1995)51:42<11431:SEFCIF>2.0.ZU;2-1
Abstract
Homolytic cycloaddition of dithiols 1,2 derived from trans- and cis-1, 2-cyclohexanediols to alkynes, induced by Pr3B-O-2, offers an extremel y simple approach to trans- and cis-cyclohexano-fused 12-membered crow n thialactones 4a-c-7a-c. The reaction of trans-1 proceeds with pronou nced remote 1,6-asymmetric induction to give predominantly (IS, 6R*, 12S)-4a-c, while cis-2 reacts nonstereoselectively. Basing an molecul ar mechanics calculations the stereoselectivity is rationalized as a r esult of entropy favored pathway of macrocyclization.