One-pot, high yield synthesis of α-ketols from Δ5-steroids
摘要:
a-Hydroxy ketones (alpha-ketols) are present in many compounds with biological activity. Several methods are available for the preparation of alpha-ketols but only a few of them describe the synthesis of steroid alpha-ketols from olefins. In this work, a new system consisting of KMnO4/Fe(ClO4)(3)center dot nH(2)O was used in order to achieve the direct conversion of Delta(5)-steroids to their corresponding alpha-ketols, in high yields. Consideration of the probable reaction mechanism is provided. 2D homo- and heteronuclear correlation NMR spectroscopic techniques were used to assign H-1 and C-13 resonances of some synthesized compounds. This method has potential for the preparation of alpha-hydroxy ketones of biological interest. (c) 2005 Elsevier Inc. All rights reserved.
Hanson, James R.; Kiran, Ismail, Journal of Chemical Research, Miniprint, 1999, # 12, p. 2933 - 2944
作者:Hanson, James R.、Kiran, Ismail
DOI:——
日期:——
Reaction of androst-5-en-17-one with hypobromous acid and its use for synthesis of 19-oxygenated 5-ene and 4-en-6-one steroids
作者:Mitsuteru Numazawa、Keiko Yamada
DOI:10.1016/s0039-128x(97)00136-0
日期:1998.2
Reaction of androst-5-en-17-one (1) with hypobromous acid using a short reaction rime (30 min) along with a careful isolation procedure gave, for the first time, the addition 5 alpha-bromo-6 beta-hydroxyandrostan-17-one (3), in 43% yield. This bromohydrin was much more reactive than 5 alpha-brormo-3 beta-acetoxy-6 beta-hydroxyandrostan-17-one (4) towards KHCO3 and HClO4. The high reactivity of compound 3 was found ro be a principal reason for the difficulty in isolating this compound the addition reaction so far. 19-Hydroxyandrost-5-en-17-one (16) and androst-5-ene-17,19-dione (18), ns well ns 19-hydroxyandrost-4-ene-6,17-dione (28) and androst-4-ene-6,17,19-trione (29), were synthesised through hypoiodite reaction of the bromohydrin 3 as a key reaction. (C) 1998 by Elsevier Science Inc.
Hanson, James R.; Truneh, Almaz, Journal of the Chemical Society. Perkin transactions I, 1988, p. 2001 - 2004