h 18 2 42 2 46 1h m 2 73 1h dd j 9 1 amp 3 7 hz h 3 3 42 1h m h 2 4 01 4 03 2h m h 11 amp 11 oh 4 15 1h br s nh 2 4 28 1h br s nh 2 5 17 1h s h 12 6 68 1h s oh 6 73 1h s oh lcms negative ion mode m z 486 m u2212 h u2212 methyl 11 hydroxycorosolate 22 to a magnetically stirred ice cold 10 15 u00b0 c solution of methyl 11 ketocorosolate 360 mg 0 72 mmol in ethanol 40 ml was added sodium borohydride 1 0 g 26 mmol and the solution was slowly brought to rt and stirred for 14 h after completion of the reaction the mixture was worked up as described in example 21 to give methyl 11 hydroxycorosolate 32 mg m p 148 152 u00b0 c ir neat 3416 2927 2872 1719 1648 1455 1388 1220 1146 1047 999 960 770 cm u2212 1 1 h nmr 400 mhz cdcl 3 u03b4 0 86 6h s 2 u00d7 ch 3 0 95 3h d j 6 0 hz ch 3 1 01 1 03 12h 3 methyl singlets and a methyl doublet 2 31 1h d j 11 3 hz h 18 2 44 1h dd j 12 0 amp 4 2 hz 3 02 1h d j 9 3 hz h 3 3 80 3 83 1h m h 2 4 39 1h m h 11 5 35 1h d j 3 8 hz h 12 lcms negative ion mode m z 501 m u2212 h u2212 corosolinol 23 to an ice cold dispersion of lithium aluminum hydride 97 mg in thf 3 ml was slowly added methyl.