TY - JOUR
T1 - Bufadienolides. Part XXIII.1 14,15β-Epoxy-3β,11α-d ihydroxy-5β-bufa- 20,22-dienoIide (11 α-Hydroxyresibufogenin)
AU - Pettit, George
AU - Kamano, Yoshiaki
N1 - Funding Information:
3500 (OH), 3040 (CH), 1720-(5b) .-Method A . 14,15fl-Epoxy-3fl, 1 Ia-dihydroxy-5p-bufa-20,22-dienolide (5a) (24 mg) was acetylated with aceticanhydride (0.4 m1)-pyndine (0.5 ml). Chromatography ofthe crude product (30 mg) with ligroin-acetone (7 : 1) andrecrystallization from acetone gave the diacetate (5b) (21mg) as prisms, 1n.p. 241-243'.The mixture prepared from the olefin (2b)(0.102 g), N-iodosuccinimide (NIS) (0.110 g), acetone (19 ml),and water (3 ml) was stirred for 18 h at room temperature.The crude iodohydrin (4c) was isolated and treated withpyridine as for the synthesis of the epoxide (5a). Chro-matographic purification and recrystallization from acetonegave prisms, m.p. 241-243" (47 mg, 46%) of the diacetateThe NIS procedure of method B was repeatedwith the olefin (2b) (50 mg) and N-bromoacetamide (50 mg)in acetone-water to give firisms (5b) (20 mg, 40%), m.p.241-243' (Found: C, 69.25; H, 7.5. C,,H,,O, requires C,69-4; H, 7*5y0), vmx. 3030 (CH), 1740, 1720-1700 (con-jugated CO .and ester CO), 1635, 1535 (conjugated C X ) ,1260, 1250, 1230 (ester C-0), 954 (C=C), 840 (epoxy C-O),and 798 (C=C) cm-l, m/e (70 eV) 484, 466, 424, 406, 395,382, 364, 349, 336, 294, 273, 256, 241, 227, 213, 131, 91, and55, T 9.12 (13-Me, s), 8.89 (10-Me, s), 7-98 (lla-OAc, s),7.90 (3@-OAc, s), 6.37 (15-H, s), 4.99br (llp-H), 4433br(3a-H, s), 3-68 (23-H, d, J 10 Hz), 2.65 (21-H, d, J 3 Hz),and 2-18 (22-H, q, J 10 and 3 Hz), A,, 298 nm (E 5250).Method B.(5b).Method C.This investigation was supported by Public HealthResearch Grants from the National Cancer Institute.[2/1975 Received, 21st August, 1972
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 1973
Y1 - 1973
N2 - Synthetic procedures have been developed for conversion of gamabufotalin (3β.11 α,14-trihydroxy-5β-bufa-20.22- dienolide) (1 a) into 11 α-hydroxyresibufogenin (5a). Selective dehydration of gamabufotalin with hydrochloric acid in methanol gave the 14-ene (2a). Addition of, for example, hyprobromous acid to this olefin (2a) afforded the bromohydrin (4b) which upon treatment with pyridine easily afforded 11 α-hydroxyresibufogenin. As part of this study 11 α-hydroxybufalone (11 α,l4-dihydroxy-3-oxo-5β-bufa-20.22-dienolide) (3a) was also prepared.
AB - Synthetic procedures have been developed for conversion of gamabufotalin (3β.11 α,14-trihydroxy-5β-bufa-20.22- dienolide) (1 a) into 11 α-hydroxyresibufogenin (5a). Selective dehydration of gamabufotalin with hydrochloric acid in methanol gave the 14-ene (2a). Addition of, for example, hyprobromous acid to this olefin (2a) afforded the bromohydrin (4b) which upon treatment with pyridine easily afforded 11 α-hydroxyresibufogenin. As part of this study 11 α-hydroxybufalone (11 α,l4-dihydroxy-3-oxo-5β-bufa-20.22-dienolide) (3a) was also prepared.
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U2 - 10.1039/P19730000725
DO - 10.1039/P19730000725
M3 - Article
C2 - 4736201
AN - SCOPUS:0015542426
SN - 1470-4358
SP - 725
EP - 727
JO - Journal of the Chemical Society, Perkin Transactions 1
JF - Journal of the Chemical Society, Perkin Transactions 1
ER -