Chemical and Pharmaceutical Bulletin p. 6 - 11 (1998)
Update date:2022-08-02
Topics:
Miyashita, Akira
Suzuki, Yumiko
Okumura, Yoko
Iwamoto, Ken-Ichi
Higashino, Takeo
When α-benzylbenzoin (3a, α-benzyl-α-hydroxybenzyl phenyl ketone) was treated with potassium cyanide (1) in N,N-dimethylformamide at 80°C for 1h, the carbon-carbon bond was cleaved, resulting in the formation of deoxybenzoin (4a, benzyl phenyl ketone) and benzaldehyde (2a). This carbon- carbon bond cleavage proceeds through a retro-benzoin condensation mechanism. This method of synthesizing ketones was applied to several α-substituted benzoins (3), and the corresponding ketones (4) were formed in good yields. Further, we found that the cyanide ion-donating ability of tetrabutylammonium cyanide (6, Bu4NCN) is more effective than that of potassium cyanide (1, KCN). As expected from the chemical analogy between cyanide ion and azolium ylide, several azolium salts (7) can also be employed in the retro-benzoin condensation as catalysts. The benzoin derivatives 3 were synthesized in the following three ways; reaction of alkyl halide (9) with benzoin (5), Michael addition of benzoin (5) with acceptors (10), and Grignard reaction of benzils (8). Alkylation of the benzoins without isolation, followed by carbon-carbon bond cleavage, readily afforded the corresponding ketones (4).
View MoreTaizhou Chenyi chemical co. LTD,
Contact:13736652831
Address:NO.273 SHANGHAI SOUTH STREET,LUQIAO DISTRICT,ZHEJIANG PROVINCE,CHINA.
CHANGYI CITY FENGRUN FINE CHEMICAL CO.,LTD
website:http://www.fengrunhuagong.com
Contact:+86-536-7869976
Address:Changyi Coastal Economic Development Zone
Contact:+86-021-58123769
Address:No.780 of Cailun Road,Zhangjiang Hi-tech Park,Pudong,Shanghai
Beijing Harmony Chemical Co., Ltd.
Contact:86-010-84956928
Address:Room 207, Jin feng he B building, No 8 Xin Jie Kou Wai Street, Xi Cheng District, Beijing,PRC. 10008
Contact:86-931-8272767
Address:Room 602, No.461, Nanchang Road, Chengguan District, Lanzhou City, China PRC
Doi:10.1016/S0008-6215(00)84840-5
(1974)Doi:10.1002/jps.2600630910
(1974)Doi:10.1021/jm020485x
(2003)Doi:10.1039/P19740001112
(1974)Doi:10.1021/ja01216a042
(1946)Doi:10.1557/mrs2001.156
(1946)