A cationic ruthenium(II) complex catalyzes double-bond transposition of 1,1-di(boryl)alk-3-enes to generate in situ 1,1-di(boryl)alk-2-enes, which then undergo chiral phosphoric acid catalyzed allylation of aldehydes producing homoallylic alcohols with a (Z)-vinylboronate moiety. 1,2-Anti stereochemistry is installed in an enantioselective manner. The (Z)-geometry forged in the products allows their isolation in a form of 1,2-oxaborinan-3-enes, upon which further synthetic transformations are operated.

To analyze gene expression of a-fetoprotein (AFP) and AFP gene expression is shown during massive liver albumin in hepatocellular carcinoma (HCC), messenger necrosis 7 and in hepatocarcinogenesis. On the other RNAs (mRNAs) of these proteins in six human hepatoma hand, albumin gene expression begins with the initiacell lines and in 30 cases of HCC were quantitatively tion of liver organogenesis and increases gradually analyzed by competitive reverse transcription (RT) fol-with development. [8][9][10][11] Albumin transcription is known lowed by polymerase chain reaction (PCR). The tran-to be modulated by various factors such as hormones, scriptional levels of both AFP and albumin genes in the acute phase reaction, extracellular matrix, heat, -fold enhanced as compared with man hepatocellular carcinoma (HCC) and the biological that of nonneoplastic portion, and correlated with se-significance of the varied AFP transcription have not rum AFP level and tumor size (P õ .01). In contrast, been clarified yet. albumin mRNA level was not reduced in the neoplasmsIn the present study, we have developed competitive presenting enhanced AFP mRNA levels, indicating that reverse transcription followed by polymerase chain re-AFP and albumin gene expression in situ is not necessar-action (RT-PCR) assays to evaluate messenger RNA ily mutually exclusive. Prospective analysis revealed (mRNA) levels of both AFP and albumin in tissue speci- , 1995; accepted January 16, 1996. lysed, and the total RNA was extracted as described below.Supported by grants from the Ministry of Health and Welfare, and theThe experiments were performed in triplicate.Ministry of Education, and the Ministry of Culture and Science, Japan.Patients. tomography, magnetic resonance imaging, and angiography.

We report a new method for constructing propionate‐derived trisubstituted alkene motifs in a stereoselective manner. 1‐Substituted 1,1‐di(pinacolatoboryl)‐(E)‐alk‐2‐enes are generated in situ from 1‐substituted 1,1‐di(pinacolatoboryl)alk‐3‐enes through ruthenium(II)‐catalyzed double‐bond transposition. These species undergo a chiral phosphoric acid catalyzed allylation reaction of aldehydes to produce the E isomers of anti‐homoallylic alcohols. On the other hand, the corresponding Z isomers of anti‐homoallylic alcohols are obtained when a dimeric palladium(I) complex is employed as the catalyst for this double‐bond transposition. Thus, both E and Z isomers can be synthesized from the same starting materials. A B−C(sp2) bond remaining with the allylation product undergoes the Suzuki–Miyaura cross‐coupling reaction to furnish a propionate‐derived trisubstituted alkene motif in a stereo‐defined form. The present method to construct the motifs with (E)‐ and (Z)‐alkenes are successfully applied to the syntheses of (+)‐isotrichostatic acid, (−)‐isotrichostatin RK, and (+)‐trichostatic acid, respectively.