TY - JOUR
T1 - Functionalization of unactivated carbons in 3α,6- and 3α,24-dihydroxy-5β-cholane derivatives by dimethyldioxirane
AU - Iida, Takashi
AU - Shiraishi, Keisuke
AU - Ogawa, Shoujiro
AU - Goto, Takaaki
AU - Mano, Nariyasu
AU - Goto, Junichi
AU - Nambara, Toshio
PY - 2003/3/1
Y1 - 2003/3/1
N2 - Direct remote functionalization of unactivated carbons by dimethyldioxirane (DMDO) was examined for 3α,6 and 3α,24-dihydroxy-5β-cholane derivatives. DMDO oxidation of stereoisomeric methyl 3α,6-diacetoxy-5β-cholanoates caused the direct, unexpected 14α- and 17α-hydroxylations, in analogy with that of the 5α-H analogs, regardless of the differences in stereochemical configuration of the A/B-ring junction and of the acetoxyl groups at C-3 and C-6. On the other hand, the ester derivatives of 3α,24-dihydroxy-5β-cholane with DMDO were transformed into the corresponding 5β-, 14α-, and 17α-hydroxy compounds, whereas the ether derivatives yielded the 5βhydroxy, 3-oxo, and C-24 oxidized products, accompanied by their dehydrated ones.
AB - Direct remote functionalization of unactivated carbons by dimethyldioxirane (DMDO) was examined for 3α,6 and 3α,24-dihydroxy-5β-cholane derivatives. DMDO oxidation of stereoisomeric methyl 3α,6-diacetoxy-5β-cholanoates caused the direct, unexpected 14α- and 17α-hydroxylations, in analogy with that of the 5α-H analogs, regardless of the differences in stereochemical configuration of the A/B-ring junction and of the acetoxyl groups at C-3 and C-6. On the other hand, the ester derivatives of 3α,24-dihydroxy-5β-cholane with DMDO were transformed into the corresponding 5β-, 14α-, and 17α-hydroxy compounds, whereas the ether derivatives yielded the 5βhydroxy, 3-oxo, and C-24 oxidized products, accompanied by their dehydrated ones.
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U2 - 10.1007/s11745-003-1062-4
DO - 10.1007/s11745-003-1062-4
M3 - Article
C2 - 12784869
AN - SCOPUS:0038625226
VL - 38
SP - 281
EP - 287
JO - Lipids
JF - Lipids
SN - 0024-4201
IS - 3
ER -