PURE ENANTIOMERS OF BICYCLO[3.2.0]HEPT-3-EN-6-ONES AND BICYCLO[3.2.0]HEPT-3-EN-6-ENDO-OLS - RESOLUTION, ABSOLUTE-CONFIGURATION AND OPTICAL-PROPERTIES

Citation
E. Marotta et al., PURE ENANTIOMERS OF BICYCLO[3.2.0]HEPT-3-EN-6-ONES AND BICYCLO[3.2.0]HEPT-3-EN-6-ENDO-OLS - RESOLUTION, ABSOLUTE-CONFIGURATION AND OPTICAL-PROPERTIES, Tetrahedron : asymmetry, 6(9), 1995, pp. 2319-2328
Citations number
12
Categorie Soggetti
Chemistry Inorganic & Nuclear","Chemistry Inorganic & Nuclear","Chemistry Physical
Journal title
ISSN journal
09574166
Volume
6
Issue
9
Year of publication
1995
Pages
2319 - 2328
Database
ISI
SICI code
0957-4166(1995)6:9<2319:PEOBAB>2.0.ZU;2-J
Abstract
Single crystal X-ray diffraction analysis of compounds A, B and, C hel ped us to assign the absolute configurations of the enantiomers of the bicycle [3.2.0]hept-3-en-6-endo-ols 4-6. These bicyclic alcohols were easily obtained by: (i) stereoselective reductions of the bicyclo[3.2 .0]hept-3-en-6-ones 1-3, (ii) conversion into diastereoisomeric pairs using (-)-(1S,4R)-camphanic acid chloride as resolving agent, (iii) an efficient separation of diastereoisomers by flash-chromatography and, finally, (iv) a mild alkaline hydrolysis. The oxidation of pure enant iomers of the bicyclo[3.2.0]hept-3-en-6-endo-ols 4-6 with tetra-n-prop ylammonium perruthenate (TPAP) and N-methylmorpholine N-oxide (NMO) as co-oxidant furnished enantiomerically pure bicyclo[3.2.0]hept-3-en-6- ones 1-3. The different mutual disposition of carbonyl groups in the s tructure A and B justifies the different IR (KBr) signals for the carb onyls of each diastereoisomer.