Synthesis of 2,6-cis-disubstituted 4-methylenetetrahydropyrans by oxy-Michael addition
摘要:
The combination of an 'ene' reaction between a 2-(2-trialkylsilyloxyalkyl)prop-2-enyl(trimethyl)silane and an alk-1-yn-3-one mediated by zinc(II) iodide, and an intramolecular oxy-Michael reaction, provides an efficient synthesis of cis-2,6-disubstituted 4-methylenetetrahydropyrans of interest in the context of a synthesis of bryostatins. The stereoselective formation of (E)-vinylsilanes in the 'ene' reaction is of interest. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of 2,6-cis-disubstituted 4-methylenetetrahydropyrans by oxy-Michael addition
摘要:
The combination of an 'ene' reaction between a 2-(2-trialkylsilyloxyalkyl)prop-2-enyl(trimethyl)silane and an alk-1-yn-3-one mediated by zinc(II) iodide, and an intramolecular oxy-Michael reaction, provides an efficient synthesis of cis-2,6-disubstituted 4-methylenetetrahydropyrans of interest in the context of a synthesis of bryostatins. The stereoselective formation of (E)-vinylsilanes in the 'ene' reaction is of interest. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis of the C(1)C(16) fragment of bryostatins
作者:Matthew O'Brien、Nicholas H Taylor、Eric J Thomas
DOI:10.1016/s0040-4039(02)01054-7
日期:2002.7
A synthesis of the C(1)C(16) fragment 43 of the bryostatins is reported which features a stereoselective equivalent of an ‘ene’ reaction between the allylsilane 35 and the alkynone 33 and the stereoselective conjugate addition–cyclisation of the dienyl ketone 36 to give the acetal 39 after acetalisation.