5 micron mobile phase n heptane 2 propanol 90 10 v v 0 1 tfa flowrate 1 ml min detection by uv at 280 nm compound 22b rel1 u03b1 25 u2212 36 4 meoh compound 22 rel2 u03b1 25 34 8 1 h nmr 400 mhz chloroform d u25a1 ppm 1 15 d j 6 8 hz 3h 1 43 s 9h 2 54 dd j 11 9 6 2 hz 1h 2 60 2 71 m 1h 2 73 2 79 m 2h 2 81 2 96 m 3h 3 49 d j 14 1 hz 1h 3 59 d j 14 1 hz 1h 4 88 6 89 br band 1h 7 02 t j 8 5 hz 1h 7 61 7 73 m 2h the tbutylprotected derivative of 175 was separated in its pure enantiomers by chiral hplc stationary phase chiralpak ic 5 u03bc column code no wjh022830 dimensions 250 u00d7 4 6 mm mobile phase n heptane dcm ethanol 50 50 1 0 1 dea flowrate 1 ml min injection 5 u03bcl detection uv 290 nm deprotection of thus obtained pure enantiomers resulted in the isolation of the testcompounds 426 and 425 compound 426 rel1 u03b1 25 u2212 22 meoh rt 1 3.