ISSN:
1434-193X
Keywords:
Chiral benzyllithium compounds
;
Lithiation
;
Stereochemistry of electrophilic substitution
;
Semiempirical calculations
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The title compound, 6, was generated by stereospecific deprotonation of the optically active carbamate 5 with sec-butyllithium/TMEDA and proved to be configuratively completely stable in ethereal solution at -78 °C. Compared with open-chain analogs, the trend for stereoretentive substitution is enhanced. Even the reaction with trialkyltin chlorides leads to partial racemization due to competing front face attack. Semiempirical calculations point to an increased degree of pyramidalization and to a higher barrier for planarization in the cyclic benzyllithium compound, both of which disfavor the rear face attack.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
