Andrew ratz Daphniphyllum Alkaloids Evans Group Seminar, June 1993 Synthesis of Methyl Homodaphniphyllate Construction of the Methyl H0人 Homodaphniphyllate Skeleton LDA, THF 1 isomer 1. Me30BF 3. HOAC, HCI 1. LTMP. PhSecl Lawesson's 2. HO(CH2)OH OBn OBn 3. LDA, THF R=Pr 10-1 J Am 90,6177 Nouv. J. Chem. 1980. 4. 47 2D0212/8009:51AMAndrew Ratz Daphniphyllum Alkaloids Evans Group Seminar, June 1993 4:1 Construction of the Methyl Homodaphniphyllate Skeleton 1 isomer NaOMe MeOH 70% 2 steps H2SO4, Acetone 1. LTMP, PhSeCl 2. MCPBA 60% 1. Me3OBF4 2. NaBH4 3. HOAc, HCl 87% 1. Et3OBF4 2. Et3N 80% X H Et3N ClCO2Et 89% pTsOH, tol. ∆ 83% LDA, THF LDA, THF 8:1 74% Lawesson's Reagent 1. H3O+ 2. HO(CH2)2OH 3. LDA, THF R=iPr 10:1 R=Me 83:17 73% 46% 14% Synthesis of Methyl Homodaphniphyllate J. Am. Chem. Soc. 1986, 108, 5650 J. Org. Chem. 1992, 57, 2531 J. Am. Chem. Soc. 1968, 90, 6177 Nouv. J. Chem. 1980, 4, 47 + HO2C O H2N Me O O Me N O O O O O O O N N O O BnO O Me O O O BnO S N S BnO O O O N O iPr Me O N N O S BnO S N O BnO O O O Me R R BnO Br iPr Me O O Me R O O S N Me O Me OBn OBn Me N O O O O O O N Me OBn H H OBn Me N O O O N HO O Me H H OBn N OBn O O 32D-02 12/8/00 9:51 AM