Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 14. 1 Tandem cyclisation of intermediate aryloxy and arylthio radicals leading to tri-and tetra-cyclic …

RA Aitken, G Burns, JJ Morrison

Index: Aitken, R. Alan; Burns, Graham; Morrison, John J. Journal of the Chemical Society - Perkin Transactions 1, 1998 , # 23 p. 3937 - 3941

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Citation Number: 2

Abstract

Seven new stabilised phosphorus ylides 8–14 designed to undergo thermal tandem cyclisation have been prepared. Upon flash vacuum pyrolysis at 850° C, loss of Ph3PO and Me˙ results in tandem cyclisation to give benzothieno [3, 2-b] benzothiophene 16 in the case of 11 while for 8 an abstraction–rearrangement–extrusion sequence leads to 2- phenylbenzofuran 18. For 9 and 10 both types of process occur to give respectively ...