THE DEMONSTRATION OF NORMAL O->N CLAISEN REARRANGEMENT IN PURINES

Article abstract of DOI:10.1016/S0040-4020(01)82069-X

6-Allyloxy-9-benzylpurine (2) and 9-benzyl-6-propargyloxy purine (5) undergo normal thermal O->N <3,3> rearrangement, either neat or in o-dichlorobenzene.The latter leads to the novel, 1-allenyl-9-benzyl-hypoxanthine (6).The related 4-allyloxy and 4-propargyloxy quinazolines (9, 12) also undergo smooth thermal O->N Claisen rearrangement.In the case of (12), the primary allenic product is further transformed into 3-propargylquinazolin-4-one (13) and the allene dimer (14).