D. A. Evans Epoxidation of Acyclic Homoallylic Alcohols Chem 206 Bishomoallylic Alcohols(Kishi, Tet. Lett. 1978, 19, 2741) Epoxidation Cyclization of Bishomoallylic Alcohols BuOOH, vO(acac) CsHs, RT diastereoselection -9:1 The Kishi Lasalocid Synthesis (JACS 1978, 100, 2933) CO2H 0=R Me' t-BuOoH, vO(acac) ArO CHMe iastereoselection 8- 1 ACOH Evans X-206 Synthesis JACS 1988, 110, 2506 O-R t-BuOOH, vO(acac CHMe? 人人入 e h6, RT R diastereoselection 20.1 (89%)HO O CO2H Me Me Me OH O Et O Me Et Me Et H H OH A Epoxidation & Cyclization of Bishomoallylic Alcohols A H Et Me Et Me OH Ar O B Me CHMe2 Et OH OH Et Me CHMe2 Me Me Me CHMe2 Et OH Me Me H O V H R Et O O R H Me H O V H R Et O O R O R V O Et O R Me H Me H OH Et Me CHMe2 O O R Me Et OH Me O Me CHMe2 Et OH Me Me OH Et Me CHMe2 O Me OH Et R Me O OH Et R Me O iPr R Et OH Me A Et Ar Me OH Et Me N Et O OBn OH O Me Me Ph O B TBHP AcOH O O O O OH Me Me Me OH Me Me O Me OH OH OH O O Et OH Me H OH Me Me H Me O OH Me R Et iPr C TBHP D AcOH HOAc XN O Et O OBn OH Me Me OH OBn O XN Et O D F Et OH Me iPr O R Bishomoallylic Alcohols (Kishi, Tet. Lett. 1978, 19, 2741) D. A. Evans Epoxidation of Acyclic Homoallylic Alcohols Chem 206 C6H6, RT t-BuOOH, VO(acac)2 diastereoselection ~ 9 : 1 C6H6 , RT t-BuOOH, VO(acac)2 diastereoselection ~ 20 : 1 C6H6, RT t-BuOOH, VO(acac)2 diastereoselection ~ 6 : 1 2nd stereocenter is reinforcing Diastereoselection 8:1 VO(acac)2 Ar = p-MeOPh VO(acac)2 The Kishi Lasalocid Synthesis (JACS 1978, 100, 2933) E Evans X-206 Synthesis JACS 1988, 110, 2506. C6H6, RT diastereoselection 20 : 1 (89 %) VO(acac)2 ● ● ● ● ● ● ● ● ● ● ● ● ● ●