Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, N9B 3P4, Canada.
J Org Chem. 2010 Dec 3;75(23):8258-70. doi: 10.1021/jo102127q. Epub 2010 Nov 11.
The application of the Nicholas reaction chemistry of 2,7-dioxygenated naphthalenes in the synthesis of cyclohepta[de]napthalenes and in the synthesis of (±)-microstegiol (1) is presented. The substitution profile of Nicholas monosubstitution (predominantly C-1) and disubstitution reactions (predominantly 1,6-) on 2,7-dioxygenated napthalenes is reported. Application of a 1,8-dicondensation product and selected C-1 monocondensation products to the construction of cyclohepta[de]naphthalenes by way of ring closing metathesis and intramolecular Friedel-Crafts reactions, respectively, is described. Deprotection of the C-7 oxygen function to the corresponding naphthol allows tautomerization to cyclohepta[de]naphthalene-1-ones upon seven-membered-ring closure in most cases, and replacement of the C-2 oxygen function in the naphthalene by a methyl group ultimately allows the synthesis of (±)-microstegiol.
介绍了 2,7-二氧代萘的 Nicholas 反应化学在环庚[de]萘类化合物和（±）-小柱烷醇（1）合成中的应用。报道了 Nicholas 单取代（主要为 C-1）和双取代反应（主要为 1,6-）在 2,7-二氧代萘上的取代模式。描述了 1,8-二缩合产物和选定的 C-1 单缩合产物分别通过闭环复分解反应和分子内傅克反应，应用于环庚[de]萘类化合物的构建。在大多数情况下，C-7 氧官能团的脱保护导致相应的萘酚发生互变异构，在七元环闭环时转化为环庚[de]萘-1-酮，而萘中 C-2 氧官能团被甲基取代最终允许（±）-小柱烷醇的合成。
