Ngày tải lên :
03/04/2014, 16:20
... Tetrahedron, 47 (12&13), 2337-2350(1991) S A Knight, et al Tetrahedron Letters, (1975) 10 S A Knight, et al Progress in NMR Spectroscopy, Org Magn Reson., 24, 28 (1992) U S A Knight, et al Progress ... mz (%): 426 [M]" (8), 411 (2), 272 (1) 257 (3), 218 (100), 203 (33), 95 (39), 69 (52), 55 (63) CrOJCH^COOH (5) Phd FT-IR n'^^''(cm"'): 1681 (>C=0), 1600 max ^ ' (>C=C-H), 1523, 1379, 1268, 1181, ... 0,95 & (),8() 692 (mdi tin hieu 3H, d,J = l Hz, Me-29 & Me-30) Sd lieu phd '^C-NMR, bing d) 3/3-Hydroxy-urs-12-en-l 1-on (neoilexonol, 6) Cho tir tir 100 mg NaBH4 vao hdn hgp chit 5/MeOH (70 mg/3...