Rearrangements of azidoquinones VI. Thermal rearrangement of azido-1,4-quinones to 2-cyano-1,3-cyclopentenediones

Harold W Moore,Walter Weyler,H.Raymond Shelden

doi:10.1016/s0040-4039(01)88583-x

Harold W Moore, Walter Weyler + Show 1 more

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https://doi.org/10.1016/s0040-4039(01)88583-x

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Journal: Tetrahedron Letters	Publication Date: Jan 1, 1969
Citations: 14	License type: cc-by

Affiliation: University of California, Irvine

Abstract

Tetralledron Letters No.45, pPO 3947-3950, 1969. Pergamon Press. Printed in Great Britain. REARRANGEMENTS OF AZIDGQUINONlB VI. THERMAL REARRANGEMENT OF AZIDO-1, I-QUINONES TO 2-CYANO-1,3-CYCLOPENTENEDIONES Harold W. Moore, Walter Weyler, Jr., and II. Raymond ShelQn Department of Chemistry University of California Irvine, California 92664 (Xeceived in USA 18 July 1969; received in UK for publication 25 August 1969) Previously it was shown that azido-1,4-quinones undergo a highly stereoselective catalyzed ring contraction to y- cyanoalkylidlne- A Q’ ’ - butenoH&s. ’ acid Reported in the present communication is an investigation of the thermal decomposition d selected azido-1,4- quinones ( 1 ), a reaction also resulting in ring contraction giving the 2-cyano-1,3-cyclopen- tenedione ( 3) ring system. This rearrangement provides a new example of a very limited number of known methods in which thermal conversion of a six to a five membered ring can be accomplished. The general structures ( 1) and ( 3) illustrate the overall chemical transformation as indicated by the following possible mechanistic scheme (Scheme I).

Highlights

Raymond ShelQn Department of Chemistry University of California Irvine, California 92664 (Xeceivedin USA 18 July 1969; receivedin UK for publication[25] August 1969) Previously it was shown that azido-1,4-quinones undergo a highly stereoselective acid catalyzed ring contraction to y- cyanoalkylidlne- A Q’ ’ - butenoH&s. ’ Reported in the present communication is an investigation of the thermal decomposition d selected azido-1,4quinones ( 1 ), a reaction resulting in ring contraction giving the 2-cyano-1,3-cyclopentenedione ( 3) ring system
The thermal rearrangements of monoazidoquinones is formally analogous to the pyrolytic ring contraction of phenylaside to cyanocyclopentadiene[5] and a - azidotropone to o-cyanophenol
6 The possibility that such ring contractions are involved mechanistically in the observed thermal bond cleavages of certain aromatic and quinoid 1, 2-diazides 7-9 is under investigation

Summary

Introduction

THERMAL REARRANGEMENT OF AZIDO-1, I-QUINONES TO 2-CYANO-1,3-CYCLOPENTENEDIONES Raymond ShelQn Department of Chemistry University of California Irvine, California 92664 (Xeceivedin USA 18 July 1969; receivedin UK for publication[25] August 1969) Previously it was shown that azido-1,4-quinones undergo a highly stereoselective acid catalyzed ring contraction to y- cyanoalkylidlne- A Q’ ’ - butenoH&s. ’ Reported in the present communication is an investigation of the thermal decomposition d selected azido-1,4quinones ( 1 ), a reaction resulting in ring contraction giving the 2-cyano-1,3-cyclopentenedione ( 3) ring system.

Results

Conclusion