title: 1,2-Bisanionic coupling approach to 2,3-disubstituted cyclopentenols and cyclopentenones.
abstract: [reaction: see text] We describe a new approach to 2,3-disubstituted cyclopentenols and cyclopentenones through two consecutive regioselective additions of equal or different electrophiles to a cyclopentene bisanionic synthon. Indeed, on exposure to BuLi, 3-bromo-2-iodocyclopent-2-enol O-TBS ether undergoes iodine-lithium permutation with complete regioselectivity. Successive reaction of the monolithium anion with different C(sp(2))- and C(sp(3))-electrophiles affords the corresponding 2-substituted-3-bromocyclopentenol derivative. Subsequent bromo-lithium exchange with t-BuLi, followed by reaction with an equal or different electrophile, affords the desired 2,3-disubstituted cyclopentenol.
authors: Dipartimento di Chimica Organica, Università di Pavia, Italy.
authors: Marco
authors: M
authors: Luparia
authors: Alessandro
authors: A
authors: Vadalà
authors: Giuseppe
authors: G
authors: Zanoni
authors: Giovanni
authors: G
authors: Vidari