1 c11 74 2 c12 16 1 c12me 77 1 c13 21 2 c14 10 8 c15 102 9 c1 u2032 73 2 c2 u2032 65 2 c3 u2032 40 9 c3 u2032 nme 30 0 c4 u2032 68 1 c5 u2032 21 4 c6 u2032 97 2 c 3 u2033 35 7 c2 u2033 73 1 c3 u2033 49 6 c3 u2033 ome 22 0 c3 u2033 me 80 7 c4 u2033 65 1 c5 u2033 19 1 c6 u2033 0 8 c2 u2032 otms 0 8 c4 u2033 otms ms m z fab 892 m h erythromycin a 2 u2032 4 u2033 bis o trimethylsilyl 9 hydrazone 1 5 g was dissolved in ch 2 cl 2 and tea 0 5 ml was added followed by triisopropylsilyl triflate 0 67 ml the resulting mixture was stirred at ambient temperature for 2 h evaporation in vacuo gave an oil which was partitioned between tbme and water the organic layer was separated and washed with water then dried na 2 so 4 and evaporated in vacuo to give a white solid 1 6 g 91 1 hnmr 500 mhz cdcl 3 d 2 63 1h h2 1 16 3h c2c h 3 4 21 1h c3c h 1 83 1h h4 1 05 c4c h 3 3 46 1h c5c h 1 35 3h c6c h 3 1 58 1 38 2h c7c h 2 3 32 1h c8c h 1 10 3h c8c h 3 2 64 1h c10c h 1 10 3h c10c h.