The annulation of phthalides with α-alkyl/arylacrylates in the presence of LDA/LHMDS is shown to directly give alkyl/aryl-1-naphthols. The method involving a novel dealkoxycarbonylation obviates the regiochemical issues in the synthesis of polysubstituted naphthalenes, and it forms the key step in a three-step total synthesis of arnottin I, a naphthobenzopyranone natural product.
Synthesis and vasorelaxant activity of 4-(cyclic amido)-2H-naphtho[1,2-b]pyrans
作者:Wen-Fei Chiou、Shyh-Yuan Li、Li-Kang Ho、Ming-Ling Hsien、Ming-Jaw Don
DOI:10.1016/s0223-5234(01)01273-9
日期:2002.1
A series of 4-(cyclic amido)-2H-naphtho[1,2-b]pyrans related to cromakalim (1) has been prepared and their vasorelaxant activities on isolated rat thoracic aorta precontracted with phenylephrine have been evaluated. The relaxant mechanism of 3a was found not through ATP-sensitive K(+) channels as cromakalim, but through opening voltage-sensitive K(+) channels.
Allyl aryl ethers undergo accelerated Claisen and [1,3] rearrangements in the presence of a mixture of trialkylalanes and water or aluminoxanes. The ratio of ortho-, meta-, and para-Claisen products depends to a large extent on the presence of water and to a much lesser extent on the nature of the alane.
Phase-Transfer-Catalyzed Oxaziridine-Mediated Hydroxylative Phenol and Naphthol Dearomatization
作者:Charlotte Grandclaudon、Patrick Y. Toullec
DOI:10.1002/ejoc.201501340
日期:2016.1
ortho-hydroxylation of substituted phenolic substrates is reported. In the presence of a phase-transfer catalyst and a base, N-sulfonyloxaziridines react with phenols to give the corresponding 6-alkyl-6-hydroxycyclohexadienone products in moderate to good yields. The reaction proceeds in fair to good yields and excellent chemoselectivity for 2,6-disubstituted phenols, 1-naphthols, and 2-naphthols.
The reaction of 1- or 2-naphthol with allylic halides (1-chloro-3-methyl-2-butene, 1-chloro-3,7-dimethyl-2,6-octadiene, trans-1-chloro-2-butene and trans-1-chloro-2-hexene) in the presence of metallic sodium gave naphthols having the corresponding allylic group selectively.