Transformations of 2-3-Epoxy Alchohols

Transformations of 2-3-Epoxy Alchohols - Myers Opening of...

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OH BnO O OH BnO O OH BnO O OH BnO O OH BnO O O HO CH 3 H 3 C [B] CH 3 H 3 C H OH O [A] CH 3 OH OH BnO N 3 OH OH BnO CN OH OH BnO CH 3 OH OH BnO OH OH BnO OTHP [B] [A] OH O BnO H 3 CO H O S t -Bu OH OH BnO O OH BnO H 3 H OH Nu C3 t -BuSNa NaOH H 2 O OH BnO O H 3 H OH Nu C2 O O Ti(OR) 3 S t -Bu OH OH BnO Chem 2 15 Transformations of 2,3-Epoxy Alcohols Myers Behrens, C. H.; Sharpless, K. B.; Aldrichimica Acta , 1983 , 16 , 67-80. NaN 3 , NH 4 Cl, 6 aq. CH 3 OCH 2 CH 2 OH 91% LiAlH 4 Et 2 O, 0 °C 83% (CH 3 ) 2 CuLi Et 2 O, –40 °C 74% LiC > CCH 2 OTHP Et 2 O, –40 °C A 23 °C 63% KCN CH 3 OH, 23 °C 50% Nu + Nucleophile Ti(O i Pr) 4 C3 : C2 yield Et 2 NH Et 2 NH i- PrOH i- PrOH (allyl) 2 NH allyl alcohol NH 4 OBz NH 4 OAc KCN 0 1.5 0 1.5 1.5 1.5 1.5 1.5 1.7 3.7 : 1 20 : 1 100 : 1 100 : 1 100 : 1 100 : 1 65 : 1 2.4 : 1 4 90 0 88 96 90 74 73 76 Ti(O i -Pr) 4 can catalyze the addition of nucleophiles to C3 From: Caron, M.; Sharpless, K. B. J. Org. Chem. 1985 , 50 , 1557-1560. - 2 3 2 3 2 3 Opening of Terminal Epoxides: Nucleophilic opening of terminal epoxides is often highly regioselective. 85% ` -Hydroxy sulfides are readily converted into terminal epoxides.
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This note was uploaded on 04/07/2008 for the course CHEM 215 taught by Professor Shair during the Fall '07 term at Harvard.

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Transformations of 2-3-Epoxy Alchohols - Myers Opening of...

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