CeCl3·7H2O-Promoted highly chemoselective hydrolysis of 1,3-oxathio- and dithioacetals
摘要:
A highly selective hydrolysis of the 1,3-oxathio- and 1,3-dithioacetals has been achieved in high yields using CeCl3.7H(2)O-NaI in acetonitrile at reflux temperature under neutral conditions. This method is mild and compatible with a wide range of functional groups such as TBDPS. THP, PMB, MOM, allyl, propargyl. prenyl, benzyl ethers. carbamates and acetate, etc., present in the substrate. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of Two Natural Furan-Cyclized Diarylheptanoids<i>via</i>2-Furaldehyde
作者:Hatice Seçinti、Hasan Seçen
DOI:10.1002/hlca.201400274
日期:2015.7
ylethyl)furan‐2‐yl]methyl}phenol (2), were synthesized starting from 2‐furaldehyde. A Wittig reaction of 2‐furaldehyde with benzyltriphenylphosphonium bromide followed by reduction of the alkene CC bond with Mg gave 2‐(2‐phenylethyl)furan (5). Lithiation of 5 with BuLi at −78° followed by alkylation with benzyl bromide gave natural product 1. In another approach, FriedelCrafts acylation of compound
Anti selective glycolate aldol reactions of (S)-4-isopropyl-1-[(R)-1-phenylethyl]imidazolidin-2-one: application towards the asymmetric synthesis of 8-4′-oxyneolignans
作者:Mukesh Gangar、Avinash Ittuveetil、Sandeep Goyal、Anang Pal、Harikrishnan M. Harikrishnan M.、Vipin A. Nair
DOI:10.1039/c6ra22026f
日期:——
The anti selective glycolate aldol reactions of (S)-4-isopropyl-1-[(R)-1-phenylethyl]imidazolidin-2-one auxiliary have been standardized with high yields and excellent diastereoselectivities on various substituted aryl, allyl and alkyl aldehydes. The optimized reaction conditions were employed for the stereoselective synthesis of oxyneolignans.
A Novel Chemoselective Cleavage of (<i>tert</i>-Butyl)(dimethyl)silyl (TBS) Ethers Catalyzed by Ce(SO<sub>4</sub>)<sub>2</sub>⋅4 H<sub>2</sub>O
作者:Davir González-Calderón、Carlos A. González-González、Aydeé Fuentes-Benítez、Erick Cuevas-Yáñez、David Corona-Becerril、Carlos González-Romero
DOI:10.1002/hlca.201300354
日期:2014.7
(tert‐Butyl)(dimethyl)silyl (tBuMe2Si; TBS) phenyl/alkyl ethers were efficiently cleaved to the corresponding parent hydroxy compounds in good yields usingcatalyticamounts of Ce(SO4)2⋅4 H2O by microwave‐assisted or conventional heating in MeOH. Intramolecular and competitive experiments demonstrated the chemoselective deprotection of TBS ethers in the presence of triisopropylsilyl (iPr3Si; TIPS)
作者:Barry P. Clark、S.Richard Baker、John Goldsworthy、John R. Harris、Ann E. Kingston
DOI:10.1016/s0960-894x(97)10071-3
日期:1997.11
The synthesis of three novel 4-carboxyphenylglycine derivatives is described. 2-Methyl substituents increase the antagonist potency compared to (S)-4CPG at mGluR1 receptors. Resolution of compound 1 showed that the activity resided in the (+)-isomer LY367385. (C) 1997 Elsevier Science Ltd.