An Efficient Synthesis of 4-Heterofunction-Substituted 3-(1-Hydroxy)ethylazetidin-2-ones from 3-(1-Hydroxy)ethyl-4-phenylsulfinylazetidin-2-one by Reaction with Silylated Heteronucleophiles.
A novel substitution reaction of 4-sulfinylazetidin-2-one with silylated heteronucleophiles: an efficient synthesis of 4-heterofunction substituted 3-(1-hydroxy)ethylazetidin-2-ones
4-Sulfinylazetidin-2-one was reacted with silylated heteronucleophiles in the presence of a catalytic amount of zinc iodide to give the corresponding trans-4-heterofunction substituted azetidin-2-ones in high yields.
1β-Methylcarbapenem intermediates via the thiolysis of a Meldrum's precursor
5-3-[1-(tert-Butyidimethylsilyloxy)ethyl]-4-oxo-azetidin-2-yl}-2,2,5-trimethyl-[1,3]dioxane-4,6-dione (3) has been submitted to nucleophilic attack with various nucleophiles. Meldrum's moiety transesterification, C4-substitution, beta -lactam ring opening and Meldrum's moiety decarboxylation were observed. Reaction of 3 with ethanethiol and dimethylaminopyridine in ethanol quantitatively furnished ethyl 2-3-[1-(tert-butyldimethylsilyloxy)ethyl]-4-oxo-azetidin-2-yl}-thiopropionate as the 1:1 mixture of beta (7a) and alpha (8a) diastereoisomers. (C) 2001 Elsevier Science Ltd. All rights reserved.
MURAKAMI, MASAYUKI;AOKI, TSUTOMU;MATSUURA, MUNENORI;NAGATA, WATARU, J. ANTIBIOTICS, 43,(1990) N1, C. 1441-1449