ISSN:
0947-6539
Keywords:
amino alcohols
;
asymmetric syntheses
;
dihydroxylations
;
diol cleavage Horner-Wittig reaction
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Spiroepoxide 1 was prepared from quinidine and converted into β-amino alcohol 3 (86% over two steps). Dihydroxylation of enantiopure oxazatricylic olefin (E)-4 provided diastereomeric diols 5a and 5b. Stereospecific conversion of 1,2-secondary, tertiary diol 5b into tetracyclic spiroepoxide 6 was accomplished in high yield by a one-pot tosylation-cyclization procedure. 1,2-Diol cleavage with NaIO4 in 80% acetic acid afforded the new tricyclic dehydrorubanone 7, containing the 4-oxa-7-azatricyclo[4.3.1.03,7]-decan-2-one core structure. Similarly, acetylated rubanone 9 was prepared on a 20 g scale. Reduction with NaBH4 in the presence of CeCl3 provided rubanols 10a and 10b (1:1.1). Horner-Wittig reaction of 9 with diethyl cyanomethylphosphonate was (Z)-selective, furnishing unsaturated nitrile (Z)-13. Conversion into the α,β-unsaturated aldehyde (Z)-14 and reduction afforded enartiopure allylic alcohol (Z)-12, which is a new isomer of the key quinidine metabolite 15.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.1460020610
