Chemical and Pharmaceutical Bulletin
Online ISSN : 1347-5223
Print ISSN : 0009-2363
ISSN-L : 0009-2363
Studies an Acetylenic Compounds. XXIII. A New Ring Closure of 2-Propynyl Ethers
Issei IwaiJunya Ide
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1962 Volume 10 Issue 10 Pages 926-933


It has been reported that 2-naphthyl allylic ethers undergo the Claisen rearrangement to give naphthol derivatives. 2-naphthyl propargyl ether derivatives, _??_-O·CH2C≡C-R (R=H, CH3, Ph.), replacing the double bond of allylic ethers by a triple bond, do not undergo the Claisen rearrangement but a new ring-closure to give 3H-naphtho [2, 1-b] pyran derivatives. Moreover, 1-naphthyl derivatives, _??_O·CH2C≡C-Phalso undergo the same ring-closure to give 4-phenyl-2H-naphtho [1, 2-b] pyran. The structures of new pyran derivatives obtained by the new ring-closure were confirmed by the melting point, infrared and ultraviolet spectra of the authentic samples which were synthesized by another routes.

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© The Pharmaceutical Society of Japan
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