Premium
A New Three‐Component Cascade Reaction to Yield 3‐Spirocyclopropanatedβ‐Lactams
Author(s) -
Zanobini Alessandra,
Brandi Alberto,
de Meijere Armin
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500838
Subject(s) - chemistry , yield (engineering) , alkyl , ethanol , formaldehyde , carboxylate , acetylation , organic chemistry , block (permutation group theory) , medicinal chemistry , materials science , geometry , mathematics , metallurgy , biochemistry , gene
A one‐pot three‐component reaction for the direct conversion of certain alkylhydroxylamine hydrochlorides 8 (alkyl = benzyl, p ‐methoxybenzyl, benzhydryl, tert ‐butyl), formaldehyde ( 9 ) or an alkyl glyoxylate ( 10 ) and bicyclopropylidene ( 2 ) to furnish 3‐spirocyclopropanated 2‐azetidinones 7 , 11 has been developed. Microwave heating of mixtures of the three components in the presence of sodium acetate in ethanol for 15–120 min furnished the products 7 , 11 in 49–78 % yield (7 examples). A new protocol for the oxidative deprotection of the 3‐spirocyclopropanated methyl 1‐( p ‐methoxybenzyl)‐2‐carboxylate 11b ‐Me provides the β‐lactam building block 17 ‐Me in 90 % yield, and the latter can be reprotected and activated with an N‐tert ‐butoxycarbonyl (Boc) group in 82 % yield. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom