Journal of Organic Chemistry p. 78 - 85 (1992)
Update date:2022-08-05
Topics:
Swenton, John S.
Callinan, Andrew
Wang, Shaopeng
An efficient route to spiroquinol vinyl ethers involves addition of a 1-lithio-2-(trimethylsilyl)acetylene-substituted benzene to the monoethyleneketal of benzoquinone followed by desilylation/cyclization of the resulting product to give vinyl ethers of spiroquinol ketals.A high-yield photochemical conversion of these vinyl ethers of spiroquinol ketals to ketals of spiro-fused 2,5-cyclohexadienones has been developed.A complication in some of these photochemical reactions is formation of secondary products from light absorbed by the product, spiro dienone ketals.This has been solved by conducting the reaction in the presence of piper ylene, which quenches the triplet-state chemistry of the product spiro dienone ketal without altering the singlet excited-state chemistry of the quinol ketal vinyl ether.The quantum yield for the photochemical <1,3>-shift reaction in a methyl-substituted vinyl ether is 0.4.Finally, irradiation of quinol spiro vinyl ethers was also observed to give spiro dienones in good yields.Although the spiro dienone is absorbing light in competition with starting quinol vinyl ether in this system, a high yield of product was obtained.The unexpected photochemical stability of these spiro dienones is discussed.The chemistry reported herein establishes an efficient high-yield route to spiro-fused 2,5-cyclohexadienones and their ketals under very mild conditions.
View MoreShenzhen HwaGen Pharmaceutical Co., Ltd
website:http://www.rafflespt.com
Contact:+86-752-5538396
Address:Guangdong Huizhou China
Chemsigma International Co.,Ltd.
website:http://www.chemsigma.com
Contact:86-025-58748998
Address:Rm.705, 15th Building,Rd.Xinke II
Nanjing Habo Medical Technology Co., Ltd.
Contact:025-85769882
Address:No.108. Ganjiabian east. Qixia District .Nanjing
Zhuzhou Farshine Chemical Industry Co., Ltd
Contact:0086-731-28482786
Address:No. 1,Shui Xian Road, He Tang Dictrict,Hunan-412000,China
Zhejiang PRIMAR Import & Export Trade Co., Ltd.
Contact:86-570-3630818
Address:No.1Puzhuyuan,Quhua,Zhejiang Province,China324004
Doi:10.1016/j.molstruc.2010.09.014
(2010)Doi:10.1021/ja109380u
(2011)Doi:10.1007/s12039-012-0325-2
(2013)Doi:10.1002/chem.201800105
(2018)Doi:10.1039/c2gc15679b
(2012)Doi:10.1016/S0040-4039(01)80695-X
(1989)