FUNCTIONALIZED CARBOCYCLES FROM CARBOHYDRATES .12. HEXA-O-BENZYL-5-HYDROXY-PSEUDO-ALPHA-D-GLUCOPYRANOSE AND ITS C-5 EPIMER

(2S)-(2,4,5/3)-2,3,4-Tribenzyloxy-5-(tetrahydropyran-2-yloxy)cyclohexanone (9), when treated with vinylmagnesium bromide and trimethylsilylmethylmagnesium chloride, gave (1S)-(1O,2,4,5/1C,3)-2,3,4-tribenzyloxy-5-(tetrahydropyran-2-yloxy)-1-vinylcyclohexanol (10) and (1R)-(1O,2,4,5/1C,3)-2,3,4-tribenzyloxy-1-(trimethylsilylmethyl)cyclohexane-1,5-diol (16), respectively, with the S configuration at C-1 exclusively. Following oxidative cleavage of the double bond, 10 was converted into (1S)-(1O,2,4,5/1C,3)-1,2,3,4,5-pentabenzyloxy-1-(benzyloxymethyl)cyclohexane (14), the C-5 epimer 19 of which was obtained from the trimethylsilylmethyl-substituted adduct following hydroxylation of the double bond of the derived (2R)-(2,4,5/3)-2,3,4-tribenzyloxy-5-hydroxy-1-methylenecyclohexane (17). (2S)-(2,4,5/3)-2,3,4-Tribenzyloxy-5-hydroxycyclohexanone (7) was converted into its enantiomer 26 and into (1S)-(1O,2,4,5O/1C,5C)-2,3,4-tribenzyloxy-5-(trimethylsilyl)methyl-1-vinylcyclohexane-1,5-diol (28). © 1990.