Procedure:  5 mL 1-neck flask, stirbar, septum, N₂ inlet

                  A solution of 0.009 g of L-DIPT in 1.1 mL of dry CH₂Cl₂ was added to a flask containing 0.042 g of activated 4 A sieves.  The mixture was stirred and cooled to -23 C.  Added 0.008 mL of Ti(O-i-Pr)₄ followed by 0.100 mL of TBHP (5-6 M in decane).  The mixture was stirred for 1h.  A solution of 0.100 g of alkene I in 0.100 mL of CH₂Cl₂ was then added.  After 2h, 45 min, TLC (50:50 EtOAc-hexanes, PMA) showed product spot at Rf 0.25 and unreacted alkene I at Rf 0.38 seeming to indicate that the reaction was about 50% complete. 

                  The reaction mixture was quenched with 0.25 mL of an FeSO₄-7H₂O, tartaric acid solution.  The mixture was warmed to 0 C, stirred for 10 min. and filtered through Celite.  The filtrate was extracted with Et₂O.  The organic layers were combined and stirred with 5.0 mL of 30% NaOH in brine at 0 C for 2h.  This mixture was then extracted again with Et₂O.  The organic layer was dried over MgSO₄, filtered and the solvent was removed by rotary evaporation.  The product was isolated by flash chromatography on silica gel using 50:50 EtOAc-hexanes as eluant.   The product is a clear, glassy solid. 

 

NB:  Also collected 0.035 g of unreacted alkene. 

 

[a]_D (product) -27.84 (c = 1.8, CHCl₃)

[a]_D (recov. s.m.) +3.10 (c = 3.2, CHCl₃)

 

¹H NMR (CDCl₃, 400 MHz) d 8.24 (bs, NH), 7.79 (m, ArH), 7.56 (m, ArH), 7.47 (m, ArH), 5.74 (dq, J = 15.4, 6.6 Hz, H7), 5.49 (ddq, J = 15.4, 7.4, 1.5 Hz, H6), 4.76 (dd, J = 6.2, 5.1 Hz, H4), 4.35 (dd(apparent t), J = 6.6 Hz, H5), 3.94 (ddd, J = 12.9, 5.5, 2.2 Hz, H1), 3.62 (ddd, J = 12.9, 7.5, 4.1 Hz, H1), 3.24 (dd, J = 5.2, 2.3 Hz, H3), 3.15(m, H2), 1.79 (dd, J = 6.6, 1.1 Hz, H8), 1.71 (dd, J = 6.6, 1.1 Hz, H8), 0.85 (s, SiC(CH₃)₃), 0.06 (s, SiCH₃), 0.02 (s, SiCH₃). 

 

notes

 

To determine whether an olefin is matched or mismatched, orient the small group toward the face of the double bond being oxidized.  The matched case is the more facile reaction.