antitumor agents are currently in phase II clinical trials for the treatment of a variety of forms of cancer. Aldol reactions and directed reductions are among the essential steps for the formation of fragments A-C in the total synthesis of the title compound. Coupling of these fragments by sulfone-based olefination and alkylation reactions was followed by macrocyclization and introduction of the enoate moieties
Practical and Robust Method for Regio- and Stereoselective Preparation of (<i>E</i>)-Ketene <i>tert</i>-Butyl TMS Acetals and β-Ketoester-derived <i>tert</i>-Butyl (1<i>Z</i>,3<i>E</i>)-1,3-Bis(TMS)dienol Ethers
We developed an efficient, practical, robust method for the regio- and stereoselective preparation of (E)-ketene trimethylsilyl acetals (KSAs) derived from tert-butyl esters 1. The reaction was performed under convenient reaction conditions; LDA−TMSCl, 0−5 °C, and cyclopentyl methyl ether (CPME) solvent. Two kinds of (Z)- and (E)-KSAs derived from α-oxygen and α-nitrogen-substituted tert-butyl esters
Regioselective Synthesis of New 1-Aminopyrroles and 1-Amino-4,5,6,7-tetrahydroindoles by One-Pot ‘Conjugate Addition/Cyclization’ Reactions of 1,3-Bis(silyl enol ethers) with 1,2-Diaza-1,3-butadienes
Unknown functionalized 1-aminopyrroles and 1-amino-4,5,6,7-tetrahydroindoles were prepared under mild conditions and with excellent yields by one-pot 'conjugate addition/cyclization' reactions of 1,3-bis(silyl enolethers) with 1,2-diaza-1,3-butadienes.