7 79 1h 5 29 dd j 15 02 7 79 1h to a solution of the acid 2 4 g 8 mmol and u03c9 n boc l lysine methyl ester hydrogen chloride salt 2 4 g 8 mmol indmf 30 ml cooled in an ice water bath was injected triethylamine 6 7 ml 48 mmol followed by addition of pybop 4 70 g 8 mmol stirring was continued at 0 u00b0 c for 2 hrs and rt for 3 hrs the resulting mixture was diluted with etoac 150 ml and then washed with aqueous nahco 3 brine dried over na 2 so 4 the etoac solution was concentrated and the residue was flush chromatographed on silica gel to afford the product as a white solid 3 59 g 83 diastereomeric excess gt 95 by 1 h nmr 1 h nmr cdcl 3 6 04 1h d 5 40 1h dd 4 96 1h dd 4 76 1h broad 4 64 1h m 4 58 2h s 3 76 3h s 3 46 2h m 3 34 3h s 3 08 2h q 2 28 1h m 1 96 2 16 2h m 1 84 1h m 1 14 1 68 10 m 1 46 9h s 0 98 6h d 0 86 6h d ms esi 543 m 1 to a solution of the amide 3 30 g 6 10 mmol in meoh 36 ml was added 4n hcl in 1 4 dioxane 12 ml the resulting solution was stirred at rt for 7 hrs and then concentrated under.