Acid catalyzed rearrangement of certain cyclopropane derivatives

✍ Scribed by Laszlo L. Darko; Joseph G. Cannon

• Publisher: Elsevier Science
• Year: 1966
• Tongue: French
• Weight: 142 KB
• Volume: 7
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)72958-3

✦ Synopsis

In the course of a study of the ozonoTysis of phenylcyclopropylethynyl carbinol in attempts to form phenylcyclopropylglycolic acid, a compound was isolated which was neither the anticipated product nor the starting material (1). Structure I was proposed for this anomalous product, based upon certain chemical reactions, nuclear magnetic resonance and infrared spectra, and elemental analytical data. However, Roberts (2) on the basis of a reinterpretation of the nuclear magnetic resonance spectrum of the anomalous product, suggested the possibility that structure II might be the correct one. * To whom correspondence should be addressed. 423 No.4 425 That I I, 3-phenyld ,i-dihydm-d-pyrone , is indeed the anomalous product was pmven unequivocally by the synthetic mute shown i'n Scheme 1. I-(3-hydmxypropyI)-pheeylacetonitrile (III) was prepared from phenylacetonitrile by lithium exchange followed by a trimethylene oxide ring-opening reaction (3). Hydrolysis of Ill with either sodium hydroxide or hydrochloric acid gave the corresponding hydroxy acid (IV), and this product spontaneously cyclized to aL-phenyl-6 -valemloctone.