Stereoselective synthesis of exocyclic allenes by double hydride reduction of 3-alkynyl-2-cycloalkenones

被引：5

作者：

Gubbels, Matthew A. ^{[1
]}

Hulce, Martin ^{[1
]}

Kum, John M. ^{[1
]}

Urick, Andrew K. ^{[1
]}

Villa, Eric M. ^{[1
]}

机构：

[1] Creighton Univ, Dept Chem, Omaha, NE 68178 USA

来源：

TETRAHEDRON | 2016年 / 72卷 / 40期

关键词：

Allene; Reduction; Hydride; Red-Al; LITHIUM ALUMINUM-HYDRIDE; STEREOCONTROLLED TOTAL-SYNTHESIS; ENANTIOSELECTIVE SYNTHESIS; STEREOSPECIFIC SYNTHESIS; THERMAL REARRANGEMENTS; ASYMMETRIC-SYNTHESIS; PROPARGYL ALCOHOL; ESTERS; 1,6-ADDITION; CAROTENOIDS;

D O I：

10.1016/j.tet.2016.07.058

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Exocyclic allene natural products and pharmaceutical agents are rare but interesting compounds: Fucoxanthin, grasshopper ketone, and analogues of prostacyclins, cephalosporins, antithrombic agents and sterol biosynthesis inhibitors are representative. Syntheses of exocyclic allenes commonly rely on extended conjugate additions to e.g., alk-2-en-4-ynones, syn S(N)2'-like additions to alkynyl oxiranes, and substitution reactions such as electrophilic substitutions of propargylic silanes. We report that the reaction of 3-alkynyl-2-cycloalkenones with 2 equiv of various hydridoaluminates but not hydridoborates proceeds via diastereoselective 1,4-reduction of a vinylogously propargylic intermediate alcoholate to provide exocyclic allenes as major products. Isomeric 3-alkynylcycloalkanols also are observed. (C) 2016 Elsevier Ltd. All rights reserved.

引用

页码：6052 / 6063

页数：12

共 98 条

[1] Large scale synthesis of N-benzyl-4-formylpiperidine through partial reduction of esters using aluminum hydride reagents modified with pyrrolidine [J].