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K Tomooka

Publications and source records attributed to K Tomooka.

9 recordsLinked to original sources
PubMed2000

External chiral ligand-induced enantioselective versions of the [2,3]-Wittig sigmatropic rearrangement.

The external chiral ligand-induced enantioselective [2,3]-Wittig rearrangements of crotyl benzyl ethers and crotyl propargylic ethers are described. The most notable is that treatment of (E)-crotyl propargylic ethers with a t-butyllithium/(S;S)-bis(oxazoline) complex provides a relatively high enantioselectivity (up to 89% ee), together with a high threo-diastereoselectivity. Furthermore, examples of the "asymmetric catalytic version" of the rearrangement of crotyl benzyl ethers are presented.

Journal Article↗
PubMed1999

Enantioselective

Even with only a catalytic amount of chiral bis(dihydrooxazole) 1 as external ligand, the rearrangement of benzyl ethers to alcohols [Eq. (1)] proceeds with high enantioselectivity (over 60 % ee). This reaction represents the first example of an enantioselective [1,2] Wittig rearrangement.

Journal Article↗
PubMed1993

Plasma concentration of human atrial natriuretic hormone in patients with connective tissue diseases.

Atrial natriuretic peptide (ANP), a peptide released from the cardiac atria, compensates blood volume expansion by its diuretic, natriuretic and vasoactive properties. We measured human plasma ANP(hANP) levels in patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and progressive systemic sclerosis (PSS) and found that their values were higher than those of healthy controls. In SLE patients, hANP levels correlated with serum creatinine concentration and the patients with proteinuria showed high levels of hANP. Administration of large amount of corticosteroid as a remission induction of the patients with SLE caused high levels of hANP. In patients with PSS, %FEV1 showed strong inverse correlations between hANP levels, and the patients with an enlarged second curvature of the heart had high levels of hANP. In patients with RA, no significant correlation was found between hANP levels and clinical variables including patients' age.

Adult↗
PubMed1989

[Serum complement levels in patients with rheumatoid arthritis and vasculitis].

It is known that serum complement levels are decreased in patients with rheumatoid arthritis associated with vasculitis, also called malignant rheumatoid arthritis (MRA). The complement profiles in patients with MRA were compared with those in uncomplicated rheumatoid arthritis (RA) and in those with systemic lupus erythematosus (SLE). In MRA patients, serum CH50, C4 and C3 levels were all decreased as in SLE patients; and C3d, an activation product of C3, and the C3d/C3 ratio as a C3 activation index were increased. Serum B level was also increased as in RA patients, but AH50 level as the haemolytic activity of the alternative pathway was within the normal range. The regulatory proteins, H and I, were elevated in sera of MRA patients. Circulating immune complexes (CIC) detected by a solid phase C1q binding method were increased, whereas the serum activity to solubilize a performed immune complex (CRA) was decreased in MRA sera. It was suggested that increased consumption of complements, mainly through the classical pathway may be responsible for the complement profiles in MRA patients: a markedly consumed classical pathway and relatively preserved alternative pathway.

Adult↗
PubMedDate not supplied

Malignant fibrous histiocytoma of the liver.

Malignant histiocytoma of the liver, a rare liver tumor, has not been reported in the radiological literature. The differential diagnosis of liver mass should be expanded to include primary malignant fibrous histiocytoma. Embolization of the mass was ineffective.

Aged↗