75950-74-2Relevant academic research and scientific papers
3aH-Indenes. Part 2. Cycloaddition Reactions of 3-Methoxy- and 3-Trimethylsiloxy-3a-methyl-3aH-indene
McCague, Raymond,Moody, Christopher J.,Rees, Charles W.
, p. 2399 - 2407 (2007/10/02)
The title 3a-methyl-3aH-indenes (1a) and (1b) have been prepared from indan-1-one via the dienone (5) and the trienone (6), and the preparation of the key intermediates (5) and (6) has been improved.The 3aH-indene (1b) behaves similarly to the methoxy derivative (1a), and rearranges on heating to the 1H-isomer.Cycloaddition reactions of (1a) to N-phenylmaleimide and maleic anhydride give isolable -adducts (12), which rearrange on heating to give the exo- and endo--adducts (13) and (14).In contrast, both 2-chloroacrylonitrile and 2-chloroacryloyl chloride give - adducts with (1a).The 2-chloroacryloyl chloride adducts are readily converted into the tricyclic ketone (23).The trimethylsiloxy 3aH-indene (1b) undergoes cycloaddition reactions with dimethyl acetylenedicarboxylate, 2-chloroacryloyl chloride, and dichloroketene.The trimethylsilyl derivative (1b) offers some advantages over the methoxyindene (1a) in synthetic work.
