Diastereoselective Die/s-Alder Reactions. Chiral Dienes co Me le,100℃c SiMe2Ph SiMegPh Fleming, JCS Perkin Trans L, 1989, 2023-2030. L Diastereoselection 82: 18 Fleming JCS Perkin Trans 1, 1989, 2023-2030 10 days OMe PhMe,100℃ OSiEr COmE R Franck, J Am. Chem. Soc. 1988, 110, 3257 Diastereoselection 12: 88 OSiMe3 R Franck, J. Am. Chem. Soc. 1988, 110, 3257 Diastereoselection 27: 73 a Rationalization for diastereofacial selectivity Allylsilane Dienophile Dienophile inside SiMe= Ph Allylic Ether Dienophile OSiMe3 ee Houk Co-workers Science. 1986. 221. 1108-1117 10A-02-Diels-Alder 10/8/00 8: 11 PM Also see A Kozikowski. J. Am. Chem. Soc. 1987. 109. 5167-5175Also see A. Kozikowski, J. Am. Chem. Soc. 1987, 109, 5167-5175. Allylic Ether Allylsilane Favored diene conformers in reactions with acetylenic dienophiles Dienophile ■ Rationalization for diastereofacial selectivity: Fleming, JCS Perkin Trans I, 1989, 2023-2030. Diastereoselective Diels–Alder Reactions: Chiral Dienes Diastereoselection 82 : 18 Diastereoselection 12 : 88 R. Franck, J. Am. Chem. Soc. 1988, 110, 3257 Dienophile Dienophile Dienophile Dienophile PhH, rt PhH, 60 °C 10 days 2 days (96%) (90%) 2 days PhMe, 100 °C Dienophile Dienophile Dienophile R. Franck, J. Am. Chem. Soc. 1988, 110, 3257 Diastereoselection 27 : 73 Diastereoselection >99 : 1 Fleming, JCS Perkin Trans I, 1989, 2023-2030. PhMe, 100 °C 2 days (72%) (62%) See Houk & Co-workers Science, 1986, 221, 1108-1117. anti outside inside Dienophile Me H SiMe2Ph Me PhN O O NPh O O H SiMe2Ph Me Me H H H NPh O O H OSiMe3 Me Me H H H H H H Me Me OSiMe3 H O O NPh SiMe2Ph Me H H H Me Me Me SiMe2Ph H O O NPh O O PhN Me OSiMe3 H Me H Me H Me OSiMe2 Me Me3SiO H Me Me Me H H OSiMe3 Me PhMe2Si Me Me Me3SiO H Me Me H OSiMe3 Me Me H OSiMe3 Me CO2Me CO2Me CO2Me CO2Me CO2Me CO2Me CO2Me CO2Me H SiMe2Ph Me Me Me H H Me SiMe2Ph CO2Me CO2Me CO2Me CO2Me Me H OSiMe3 Me Me H H H Me Me Me OSiMe3 H SiMe2Ph H Me Me SiMe2Ph H Me CO2Me CO2Me CO2Me CO2Me H SiMe2Ph H Me SiMe2Ph H Me Me PhMe2Si Me 10A-02-Diels-Alder 10/8/00 8:11 PM