Stereoselective cycloaddition–lactonization reaction of 2-allyl-4-pentenoic acids with polyfluoroalkyl iodides. An efficient synthesis of polyfluoroalkyl-containing bicyclolactone derivatives
Polyfluoroalkyl-containing bicyclolactones were synthesized via the sodium dithionite-initiated cyclo-addition lactonization reaction of 2-allyl-4-pentenoic acids and polyfluoroalkyl iodides. The chemo- and stereo-selectivity of the cycloaddition lactonization reaction strongly depended on the space hindrance of 2-substituent in 2-allyl-4-pentenoic acids. The reaction was believed to proceed through a tandem free radical addition-lactonization process. (C) 2010 Elsevier Ltd. All rights reserved.
Highly enantioselective creation of quaternary carbons in a halolactonization of bis-γ,δ-unsaturated carboxylic imides derived from a camphorsultam: Enantioselective synthesis of (+)-mesembrine
Iodolactonization of symmetrical diene-carboxylic imides (3a,b), derived from a camphorsultam, afforded chiral lactones (5) and (6) possessing aromatic substituents on quaternary carbons in high enantioselectivity with moderate diastereoselectivity.