81280-24-2Relevant 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.
Generation of 3-Methoxy-3a-methyl-3aH-indene and Study of its Cycloaddition Reactions
Gilchrist, Thomas L.,Rees, Charles W.,Tuddenham, David
, p. 3214 - 3220 (2007/10/02)
The title compound (1) has been prepared from indan-1-one by Birch reduction and methylation followed by the introduction of a further double bond, enolisation of the ketone, and O-methylation.The tetraenol ether (1) is the first 3aH-indene derivative to be isolated.It is shown to be oxidised by air to the Z-cinnamic ester (5), and to undergo ready rearrangement to the 1H-indene (7).Cycloadditions of N-phenyltriazolinedione, diethyl azodiformate, and dimethyl acetylenedicarboxylate to the termini of the tetraene are observed.These formal cycloadditions are in contrast to the addition which is observed with N-phenylmaleimide.The adduct rearranges on heating to give a mixture of adducts: it is suggested that this process involves dissociation of the adduct into its components and their re-combination.
