共 5 条
Reexamination of products and the reaction mechanism of the chalcogeno-Baylis-Hillman reaction:: Chalcogenide-TiCl4-mediated reactions of electron-deficient alkenes with aldehydes
被引:57
|作者:
Kataoka, T
Kinoshita, H
Iwama, T
Tsujiyama, S
Iwamura, T
Watanabe, S
Muraoka, O
Tanabe, G
机构:
[1] Gifu Pharmaceut Univ, Gifu 5028585, Japan
[2] Kinki Univ, Fac Pharmaceut Sci, Higashiosaka, Osaka 5778502, Japan
来源:
关键词:
aldols;
enones;
sulfides;
titanium and compounds;
D O I:
10.1016/S0040-4020(00)00396-3
中图分类号:
O62 [有机化学];
学科分类号:
070303 ;
081704 ;
摘要:
Reactions of p-nitrobenzaldehyde (4) with methyl vinyl ketone (5) were conducted in the presence of TiCl4 and dimethyl sulfide (3) or selenopyranone 6. When the raw product was purified by column chromatography on silica gel, alpha-chloromethyl aldol 8 was obtained as a mixture of diastereoisomers 8a and 8b. In contrast, purification of the raw product by preparative TLC on silica gel gave alpha-methylene aldol 7. The mechanism for the formation of alpha-chloromethyl aldol 8 and diasteroselection for the syn-isomer 8a and anti-isomer 8b are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.
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页码:4725 / 4731
页数:7
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