FR901464 (I; R = Q), FR901463, i.e. I (R = Q1), and FR901465, i.e. I (R = Q2), are new antitumor substances which were isolated from a culture broth of a bacterium of Pseudomonas sp. Number2663.These compounds show transcriptional regulating activity and induce characteristic G1 and G2/M phase arrest in the cell cycle.Related to these activities, they show potent antitumor effect.Especially, FR901464 I (R = Q) exhibits the most prominent antitumor activity among the three compoundsThe unique structure as well as the significant biol. activities prompted the authors to undertake the synthesis of this class of compoundHerein, the authors describe a stereoselective synthetic approach to FR901464 I (R = Q).The retrosynthetic anal. divided FR901464 I (R = Q) into three segments, the carboxylic acid II, the sulfone III, and the aldehyde IV.The authors thought that II, III, and IV would be obtained from com. available compounds resp., and the target mol. FR901464 I (R = Q) should be synthesized via convergent route by condensations of these segments.According to this synthetic plan, the authors carried out their study.The acid II was prepared from Et (S)-(-)-lactate using the reported method.N-Boc-L-threonine was used as the starting material to synthesize III.The Garner aldehyde V was prepared from N-Boc-L-threonine.Its side chain was elongated by the Wittig reaction, and was led to a lactone VI (Z = O) by acid catalyzed ring closure.Treatment with Lawesson's reagent and the following Wittig reaction gave the olefin isomers, (E)- and (Z)-VI (Z = :CH2CO2Me).After the base catalyzed deconjugation of olefin, catalytic hydrogenation gave the tetrahydropyran with the desired all-cis stereochem. as a sole product, and the successive DIBAL reduction afforded the aldehyde (VII), which was converted into the sulfone III through 4 steps.The aldehyde IV was synthesized from 2-deoxy-D-glucose.First, 4,6-dihydroxyl groups of 2-deoxy-D-glucose were protected as benzylidene acetal.Selective oxidation of hemiacetal with bromine, followed by the protection of the remaining free hydroxyl group gave the lactone VIII.Methylation and acetalization followed by deprotection of benzylidene group afforded diol IX.It was converted into aldehyde IV via protection-deprotection process and Dess-Martin oxidationHaving completed the synthesis of the three segments II, III and IV, the authors next examined the coupling processes.Condensation of II with III was achieved by using HBTU to give the amide X.Using Julia olefination method, coupling of X and the aldehyde IV afforded the diene I (R = Q3, R1 = tert-BuMe2Si).The successive selective desilylation and oxidation afforded the diene I (R = Q4, R1 = tert-BuMe2Si).The diene I (R = Q4, R1 = tert-BuMe2Si) possesses most of the carbon framework with the requisite asym. carbons involved of FR901464, I (R = Q, R1 = Ac).Since XI (R = Q4, R1 = tert-BuMe2Si) is considered as a potential key intermediate in the authors' our synthetic strategy, conversion of XI (R = Q4) to the target mol. FR901464, I (R = Q, R1 = Ac) is now under investigation.