Convenient synthesis of (±)- and (S)-antipode of (4E,7S)-7-methoxytetradec-4-enoic acid, the antimicrobial principle of marine cyanophyte
摘要:
The (+/-)- and S-isomers of title compound I were prepared via a short and efficient route. The key features of the synthesis were the use of easily accessible materials, operationally simple reaction protocol and highly enantioselective lipase catalyzed esterification for the generation of the required chiron. Copyright (C) 1996 Published by Elsevier Science Ltd
Convenient synthesis of (±)- and (S)-antipode of (4E,7S)-7-methoxytetradec-4-enoic acid, the antimicrobial principle of marine cyanophyte
摘要:
The (+/-)- and S-isomers of title compound I were prepared via a short and efficient route. The key features of the synthesis were the use of easily accessible materials, operationally simple reaction protocol and highly enantioselective lipase catalyzed esterification for the generation of the required chiron. Copyright (C) 1996 Published by Elsevier Science Ltd
Asymmetric synthesis of 3-substituted 3,4-dihydroisocoumarins via stereoselective addition of laterally lithiated chiral 2-(o-tolyl)oxazolines to aldehydes followed by diastereomer-selective lactonization
作者:Yuji Kurosaki、Tsutomu Fukuda、Masatomo Iwao
DOI:10.1016/j.tet.2005.01.103
日期:2005.3
Lateral lithiation of (S)-4-isopropyl-2-(o-tolyl)oxazoline in diethyl ether followed by the reaction with aldehydes in the presence of TMEDA produced the addition products with stereoselectivities up to 84% de. Utilization of TMEDA as a ligand is essential for the good selectivity. Rationale for the stereoselectivity is proposed based on ab initio calculation of the lateral lithio species. The major
Enantio- and diastereocontrolled conversion of chiral epoxides to trans-cyclopropane carboxylates: application to the synthesis of cascarillic acid, grenadamide and <scp>l</scp>-(−)-CCG-II
作者:Pradeep Kumar、Abhishek Dubey、Anand Harbindu
DOI:10.1039/c2ob25622c
日期:——
An efficient high yielding improved method for the enantio- and diastereoselective cyclopropanation of chiral epoxides using triethylphosphonoacetate and base (Wadsworth–Emmons cyclopropanation) is reported. The utility of this protocol is illustrated by concise and practical synthesis of cascarillic acid, grenadamide and L-(−)-CCG-II, a cyclopropane containing natural products.