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Please login or sign up for a free trial to access the full content. Stoichiometric Nazarov Cyclizations

DOI: 10.1055/sos-SD-203-00232

Gaspar, B.; Trauner, D.Science of Synthesis: Stereoselective Synthesis, (20113386.

The introduction of a silicon directing group can control the regioselective formation of the less substituted double bond in the cyclopentenone products.[‌17‌] For example, the vinylogous acylsilanes 18 undergo an iron(III) chloride mediated cyclization to afford the cyclopentenones 19 in moderate to excellent yield, favoring the cis-fusion in the bicyclic system (Scheme 6).[‌18‌] Various saturated and unsaturated chains, in addition to heteroatoms, are well tolerated in the reaction.

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M8,M8 M8 Meee (°M) Meee (e) Meeee (%) Mee
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(MM8)8 M 8 8 88 [‌88‌]
(MM8)8 M 88 8.8 88e [‌88‌]
(MM8)8MMe8MM8 M 8 8 88 [‌88‌]
MM=MMMMe8MM8 M 88 8 88 [‌88‌]
(MM8)8MM(MMe) M 8 8 88 [‌88‌]
(MM8)8M M 88 8 88 [‌88‌]
(MM8)8M(MM8Me) M 88 88 88e [‌88‌]
(MM8)8 M 8 8 88e [‌88‌]

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M8 M8 M8 ee (%) Meeeee Meeee (%) Mee
M (MM8)8MM=MM8 eMe 88 88 [‌88‌]
M Me e-Me 88 88 [‌88‌]
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