Synthesis of 2-indanones via [4 + 1] annulation reactions of (trialkylsilyl)arylketenes.
[reaction: see text] (Trialkylsilyl)arylketenes combine with (trimethylsilyl)diazomethane in a new [4 + 1] annulation process leading to 2-indanone derivatives. The (trialkylsilyl)arylketene annulation substrates are available via the photochemical Wolff rearrangement of alpha-silyl-alpha-diazo ketones, which are themselves prepared by silylation of the corresponding diazo ketones. The mechanism of the annulation reaction is proposed to involve the formation of a 2,3-bis(silyl)cyclopropanone, which is in equilibrium with an oxyallylic cation. Electrocyclic closure of this intermediate forms the new cyclopentenone ring.
Dalton
Audra M
AM
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Zhang
Yongjun
Y
Davie
Christopher P
CP
Danheiser
Rick L
RL
D003517:Cyclopentanes / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry; D007189:Indans / Q000138:chemical synthesis*; D007659:Ketones / Q000737:chemistry; D014297:Trimethylsilyl Compounds / Q000737:chemistry
D003517:Cyclopentanes; D005030:Ethylenes; D007189:Indans; D007659:Ketones; D014297:Trimethylsilyl Compounds; C013352:indacrinone; C008223:ketene; C013905:cyclopentenone