Synthesis of 1-[cis-3-(hydroxymethyl)cyclobutyl]-uracil, -thymine and -cytosine
作者:Miriam Frieden、Matthieu Giraud、Colin B. Reese、Quanlai Song
DOI:10.1039/a803878c
日期:——
4-(Benzylsulfanyl)pyrimidin-2(1H)-one 6a is prepared from 1-benzoyluracil 10a in three steps and in satisfactory overall yield. Reproducible conditions are found for the cycloaddition reaction between allyl benzyl ether and dichloroketene, leading to the cyclobutanone derivative 17 in good yield. trans-3-(Benzyloxymethyl)cyclobutan-1-ol 15 reacts under standard Mitsunobu conditions with the pyrimidine derivative 6a on O-2 to give compound 20, which is converted into 2-[cis-3-(hydroxymethyl)-cyclobutoxy]pyrimidin-4(3H)-one 24 in good overall yield. Under the same Mitsunobu conditions, 3-benzoyluracil 11a and 3-benzoylthymine 11b react with the trans-alcohol 15 on N-1 to give their 1-[cis-3-(benzyloxymethyl)cyclobutyl] derivatives 27a and 27b, respectively. The latter compounds 27a and 27b are converted into 1-[cis-3-(hydroxymethyl)cyclobutyl]uracil 13a and 1-[cis-3-(hydroxymethyl)cyclobutyl]thymine 13b in satisfactory overall yields. The uracil derivative 13a is converted into 1-[cis-3-(hydroxymethyl)cyclobutyl]cytosine 14 in good yield.
An efficient route to 3-substituted cyclobutanone derivatives
作者:George W. Kabalka、Min-Liang Yao
DOI:10.1016/s0040-4039(03)00081-9
日期:2003.2
An efficient route to 3-(hydroxymethyl)cyclobutanone acetals via a [2+2] cycloaddition reaction is reported. The dramatic effect of different diol acetals on benzyl deprotection is discussed. Efficient synthesis of two synthetically usefulintermediates, 3-methylenecyclobutanone acetal and 3-(bromomethyl)cyclobutanone, are provided.
[EN] SOLID-PHASE PREPARATION OF <18>F-LABELLED AMINO ACIDS<br/>[FR] PREPARATION EN PHASE SOLIDE D'ACIDES AMINES MARQUES AU <18>F
申请人:AMERSHAM PLC
公开号:WO2004056725A1
公开(公告)日:2004-07-08
A process for the production of an 18F-labelled tracer which comprises treatment of a solid support-bound precursor of formula (I): SOLID SUPPORT-LINKER-SO2-O -TRACER (I) with 18F- to produce the labelled tracer of formula (II).
Direct Syntheses of Spiro- and Fused-Hydrofurans by a Tunable Tandem Semipinacol Rearrangement/Oxa-Michael Addition Protocol
作者:Bao-Sheng Li、Wen-Xing Liu、Qing-Wei Zhang、Shao-Hua Wang、Fu-Min Zhang、Shu-Yu Zhang、Yong-Qiang Tu、Xiao-Ping Cao
DOI:10.1002/chem.201300205
日期:2013.4.22
one‐pot reaction has been developed involving a tandemsemipinacolrearrangement/oxa‐Michael addition sequence in which the in situ generated ketol diene intermediate can be transformed specifically to either the spiro‐ or fused‐dihydrofuran products (see scheme). This one‐pot tandem reaction represents a general synthetic methodology for the syntheses of the two different kinds of furan derivatives
Palladium-Catalyzed Asymmetric Ring Expansion of Allenylcyclobutanols: An Asymmetric Wagner−Meerwein Shift
作者:Barry M. Trost、Jia Xie
DOI:10.1021/ja0602501
日期:2006.5.1
In this study, we developed a palladium-catalyzed atom economic asymmetricWagner-Meerweinshift of allenylcyclobutanol substrates. It is an excellent method for creating functionalized cyclopentanones with an alpha-chiral O-tertiary center by ring expansion of allenylcyclobutanols. This reaction was initiated by hydropalladation and afforded excellent enantioselectivity as well as atom economy. This