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The Aldol Reaction of Allenolates with Aldehydes in the Presence of Magnesium Diiodide (MgI 2 ) as Catalyst
Author(s) -
Deng GuangHui,
Hu Hui,
Wei HanXun,
Paré Paul W.
Publication year - 2003
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200390294
Subject(s) - chemistry , catalysis , adduct , magnesium , stereoselectivity , aldol reaction , selectivity , trimethylsilyl , medicinal chemistry , aldehyde , coupling reaction , organic chemistry
Stereoselective synthesis of ( Z )‐ α ‐(hydroxyalkyl)‐ β ‐iodoacrylates (=(2 Z )‐2‐(hydroxyalkyl)‐3‐iodoprop‐2‐enoates) was achieved in a one‐pot coupling reaction from methyl prop‐2‐ynoate, Me 3 SiI, and an alkanal under mild conditions with MgI 2 as catalyst (→ 1 – 9 ; see Table and Scheme 1 ). Baylis‐Hillman β ‐iodo adducts were generated in excellent yields with high ( Z )‐selectivity. The conversion of methyl prop‐2‐ynoate to an active methyl 3‐iodo‐1‐[(trimethylsilyl)oxy]allenolate intermediate in situ followed by carbonyl addition is proposed as the reaction sequence ( Schemes 1 and 2 ).