Subscribe to RSS
DOI: 10.1055/s-2001-14650
Pentadienyltitaniums as Versatile Intermediates: Regio- and Stereoselectivities
Publication History
Publication Date:
31 December 2001 (online)
The adduct obtained upon consecutive treatment of 1,4-dienes with butyllithium in the presence of potassium tert-butoxide, chlorotri(isopropyloxy)titanium and a carbonyl compound contains the α-hydroxyalkyl group invariably and exclusively linked to the 3-position of the former diene. When chlorotri(isopropyloxy)titanium is replaced by the Duthaler-Hafner reagent [4R,5R)-chloro(cyclopentadienyl)(2,2-dimethyl-α,α,α′,α′-tetraphenyl-1,3-dioxolane-4,5-dimethanolato-O,O α )titanium] the reaction does not only occur regioselectively but also with appreciably high enantioselectivity.
superbase - metal effects - regioselectivity of electrophilic attack - stereoselectivity of carbon-carbon bond formation - natural product synthesis