A fluoroisoprenylation sequence employing 2-fluoroalkenal derived azomethines as key intermediates: a stereocontrolled synthesis of 2-fluorogeraniol and 2-fluorofarnesol

Azomethines (Schiff's bases) derived from a,b-unsatd. a-fluoroaldehydes can be deprotonated with lithium diisopropylamide. The resulting \"anions\" or, correctly, 3-fluoro-1-azapentadienyl lithium compds. are conformationally mobile. While eight different coplanar structures are possible, one of them, a zigzag shaped (W) conformation must be largely favored. Depending on their nature, electrophiles attack the 1-azapentadienyl intermediates at either of the three nodal points: the nitrogen atom, the fluorine bearing a-position or the terminal g-position. Allyl type alkylating reagents produce a mixt. of a- and g-regioisomers from which the pure components can be sepd. Consecutive hydrolysis and redn. provides a-fluoroalkenals and a-fluoroallyl alcs. [on SciFinder (R)]

Published in:
Tetrahedron, 50, 26, 7827-36
CAN 121:157751
Organometallic and Organometalloidal Compounds
Institut de Chimie organique,Univ. Rue de la Barre 2,Lausanne,Switz.
written in English.
75-64-9 (tert-Butylamine) Role: RCT (Reactant), RACT (Reactant or reagent) (condensation of, with fluoroalkenals); 157492-10-9P; 157492-18-7P; 157492-19-8P; 157492-20-1P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and hydrolysis of); 157492-13-2P; 157492-14-3P; 157492-15-4P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and reaction of, with electrophile); 157492-12-1P; 157492-40-5P; 157492-41-6P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and reaction of, with tert-butylamine, azomethine from); 157492-09-6P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (prepn. and substitution reaction of); 3917-35-9P; 80359-50-8P; 157492-05-2P; 157492-06-3P; 157492-07-4P; 157492-08-5P; 157492-11-0P; 157492-16-5P; 157492-17-6P; 157492-21-2P; 157492-22-3P; 157492-24-5P; 157492-25-6P; 157492-26-7P; 157492-27-8P; 157492-28-9P; 157492-29-0P; 157492-30-3P; 157492-31-4P; 157492-32-5P; 157492-33-6P; 157492-34-7P; 157492-35-8P; 157492-36-9P; 157492-37-0P; 157492-38-1P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 870-63-3 (Prenyl bromide); 157492-23-4 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of); 76886-46-9 (1-Methoxy-2,3,3-trimethyl-1-butene); 157492-39-2 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with dichlorofluoromethane)

 Record created 2006-03-03, last modified 2018-01-27

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