ISSN:
0009-2940
Keywords:
Radical-type cyclisation / Bicyclo[3.2.]octan-3-one, enantiomerically pure / Charge-transfer interactions
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Radical-Type Cyclisation of Dienes, 111. - Radical-Type Cyclisation of (R)-( - )-Carvone - On the Influence of Charge- Transfer Interactions on the Optical RotationUnder the conditions of radical cyclisation, a 1:1 diastereomeric mixture of (1R,2S,5R,R)-(+)- (2a) and (1R.2S,5R,6S)-(+)-6-methoxy-2,6-dimethylbicyclo[3.2.1]octan-3-ones (2b) is obtained from (R)-(-)-carvone in 70% yield. the configuration fo 2a and 2b were confirmed by X-ray structure analyses of their hydrazones 2d and 2e. The regio- and stereoselectivity of the radical cyclisation of 1 to 2a and 2b are discussed. The high value of the specific rotation [-555] of 2d is traced back to charge-transfer interactions between the endo-standing methoxy group at C-6 as electron donor and the dinitrophenyl-hydrazone group as electron acceptor.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19901230441