An easy access to gamma-lactone-fused cyclopentanoids.
The tricyclic alpha-keto hemiacetals 3a,b and 8a-d obtained from ruthenium-catalyzed oxidation of tetrahalonorbornyl derivatives possessing a pendant hydroxymethyl group were cleaved using Pb(OAc)(4) or alkaline H(2)O(2) to give gamma-lactone-fused cyclopentane derivatives 5a,b and 9a-d. The alpha-keto hemiacetal 3b has also been elaborated to spiroepoxide derivative 25. The stable hydrate 4 formed from ruthenium-catalyzed oxidation of acrolein adduct 10 furnished an intramolecular hemiacetal 11 upon cleavage with Pb(OAc)(4). The alpha-halo ester moiety in 5a was transformed smoothly in a highly regio- and stereoselective manner to alpha-hydroxy esters through a lactone-assisted intermediate to furnish 18.
Khan
Faiz Ahmed
FA
Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India. faiz@iitk.ac.in
Dash
Jyotirmayee
J
Sahu
Nilam
N
Sudheer
Ch
Ch
D001685:Biological Factors / Q000138:chemical synthesis; D003517:Cyclopentanes / Q000138:chemical synthesis*; D007783:Lactones / Q000138:chemical synthesis*
D001685:Biological Factors; D003517:Cyclopentanes; D007783:Lactones