Okabayashi Tomohito, Iida Akira, Takai Kenta, Nawate Yuuya, Misaki Tomonori, Tanabe Yoo
Department of Chemistry, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan.
J Org Chem. 2007 Oct 12;72(21):8142-5. doi: 10.1021/jo701456t. Epub 2007 Sep 18.
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 degrees C, and cyclopentyl methyl ether (CPME) solvent. Two kinds of (Z)- and (E)-KSAs derived from alpha-oxygen and alpha-nitrogen-substituted tert-butyl esters, respectively, were also obtained in good yield. The present protocol was successfully applied to a stereocontrolled preparation of useful, but highly reactive (less accessible) beta-ketoester-derived tert-butyl (1Z,3E)-1,3-bis(TMS)dienol ethers 2.
我们开发了一种高效、实用、稳健的方法，用于区域和立体选择性地制备源自叔丁酯1的（E）-乙烯酮三甲基硅基缩醛（KSA）。该反应在方便的反应条件下进行：LDA-TMSCl、0-5摄氏度和环戊基甲基醚（CPME）溶剂。分别源自α-氧和α-氮取代叔丁酯的两种（Z）-和（E）-KSA也以良好的产率得到。本方案成功应用于有用但高反应性（难以获得）的β-酮酯衍生的叔丁基（1Z，3E）-1，3-双（TMS）二烯醇醚2的立体控制制备。
