Cyclic Allylic Alcohols KF, H2O2 5%, 2 steps Note: In all cases a single isomer is obta has been employed in the synthesis of branched sugars. 60%, 2 steps Ho 1)n-BuaSnH, AIBN 2)KOM-Bu, DMSO Stork. G. Sofia M. JJ. Am. Chem. Soc. 1986. 108 6826 Introduction of Angular Functionalit )n-Bu3SnH, AIBN 3 Stork, G: Mah, R. Tetrahedron Lett, 1989, 30, 3609 1)n-BujSnH, AIBN (100%) n-Bu3SnH 2)KF,H2O2(455 AIBN (100% 1)n-BU3SnH, AIBN n-Bu SnH, AIBN KF, H2O2 "Poor Yield 33A-093/14965:42PM Lejeune, J; Lallemand, J. Y. Tetrahedron Lett. 1992, 33, 2977O O Me Si Br Si Me Me Me HO OH O O Me Si Br Si Me Me Me HO OH Me Ot-Bu H Me Ot-Bu Me Ot-Bu H HO Me Me Ot-Bu H Me Me Me Me Me O Si Br Me Me Me Me Me Me Me HO Me H Me O Si Br Me Me Me HO Me H 1) n-Bu3SnH, AIBN 2) KF, H2O2 65%, 2 steps O Br Si Me Me OH OH H HO HO H H O Br Si Me Me H OH H HO H O Br Si Me Me H OTMS H O Br Si Me Me H OH O O HO H O Br Si Me Me O H O O H O 1) n-Bu3SnH, AIBN 2) KOt-Bu, DMSO 75%, 2 steps Cyclic Allylic Alcohols: Si Me Me H O Si Me Me n-Bu3SnH AIBN KF, H2O2 75%, 2 steps n-Bu3SnH AIBN KF, H2O2 88%, 2 steps KOt-Bu, DMSO 60%, 2 steps 1) n-Bu3SnH, AIBN 2) KOt-Bu, DMSO 80%, 2 steps H Note: In all cases a single isomer is obtained, resulting exclusively from 5-exo cyclization. This methodology has been employed in the synthesis of branched sugars. O Si CH3 CH3 Stork, G.; Sofia, M. J. J. Am. Chem. Soc. 1986, 108, 6826. 1) n-Bu3SnH, AIBN 2) KF, H2O2 91%, 2 steps 3.7 : 1 + n-Bu3SnH AIBN (100%) 1) n-Bu3SnH, AIBN (100%) 2) KF, H2O2 (45%) H H H O Si CH3 H3C n-Bu3SnH, AIBN "Poor Yield" 3 : 2 + Stork, G.; Mah, R. Tetrahedron Lett., 1989, 30, 3609. ‡ . Introduction of Angular Functionality: . ‡ Lejeune, J.; Lallemand, J. Y. Tetrahedron Lett. 1992, 33, 2977. 33A-09 3/14/96 5:42 PM