Journal of Organic Chemistry p. 2723 - 2728 (1988)
Update date:2022-09-26
Topics:
Tamura, Rui
Saegusa, Koji
Kakihana, Masato
Oda, Daihei
Sterically crowded allylic tributylphosphorus ylides such as β-γ-disubstituted allylic ylides react with various aldehydes to afford E olefins with high stereoselectivity (E>92percent).As the steric demand of the ylides was decreased, bulky aldehydes were required to achieve high E selectivity.On the other hand, predominant or exclusive formation of Z olefins was achieved by using allylic triphenylphosphorus ylides and tertiary aldehydes like pivaldehyde, while the combination of allylic triphenylphosphorus ylides and such large secondary aldehydes as cyclohexanecarboxaldehyde led to E olefin formation under the lithium salt free conditions.The distinct lithium salt effect was observed in the reaction effected with triphenylphosphorus ylides.The origin of the observed E or Z selectivity can be reasonably explained according to Vedejs' rationale on the Wittig reaction stereochemistry.
View MoreContact:86-574-26865651
Address:529 YuanBaoShan Road, Beilun District
Taizhou Shengxing Chempharm Co.,Ltd
Contact:+86-576-88516600
Address:Yantou Chemical Zone Jiaojiang Taizhou Zhejiang China
PINGYUAN SIHUAN PHARMACEUTICAL CO., LTD
Contact:+86-531-55696072
Address:#2766,yinxiu Road, Economic Development Zone, Pingyuan Country, Shandong Province, China.
Chengdu Green Young Biopharmaceutical INC
Contact:+86-28-85337952
Address:1-B-26,Tianhe Industry Park, No.1480 of Tianfu Road,Chengdu,P.R.China,610000
Hangzhou Deli Chemical Co.,Ltd.
website:http://www.dlchemical.com
Contact:86 571 28006267
Address:Tangxi Industrial Area, Yuhang District, Hangzhou
Doi:10.1002/cmdc.201402394
(2014)Doi:10.1021/om900182z
(2009)Doi:10.1016/S0040-4020(01)81634-3
(1987)Doi:10.1039/b821409c
(2009)Doi:10.1016/S0040-4039(00)96614-0
(1987)Doi:10.1021/ol026098z
(2002)