Reference

Evaluation of alkaline permanganate oxidation method for the characterization of young kerogen

Evaluation of alkaline permanganate oxidation method for the characterization of young kerogen. Machihara, Tsutomu; Ishiwatari, Ryoshi (Fac. Sci., Tokyo Metrop. Univ., Tokyo 158, Japan). Org. Geochem., 5(3), 111-19 (English) 1983. CODEN: ORGEDE. ISSN: 0146-6380. DOCUMENT TYPE: Journal CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Alk. KMnO4 oxidn. of a young kerogen (lacustrine) and 34 model compds. (satd. and unsatd. fatty acids, hydroxy acid, aliph. dicarboxylic acids, aliph. alcs., normal hydrocarbon, b-carotene, phenolic acids, benzenecarboxylic acids, carbohydrates, amino acids, and proteins) were conducted, followed by gas chromatog. and gas chromatog.-mass spectroscopic anal. of the degrdn. products. The stability of the degrdn. products of kerogen in permanganate soln. and the relation between degrdn. products and kerogen building blocks were detd. The results showed that aliph. acids (C12-C16 monocarboxylic acids and C6-C10 a,w-dicarboxylic acids) were rather susceptible to oxidn. compared with benzenecarboxylic acids, and the former were degraded into lower mol. wt. decarboxylic acids. Oxidn. at milder conditions (60°, 1 h) is appropriate for qual. and quant. characterization of the aliph. structure of young kerogen. It was noteworthy that benzoic acid [65-85-0] was produced in a significant amt. by oxidn. of amino acids (phenylalanine) and proteins, C18-isoprenoidal ketone from phytol, and C8 and C9 a,w-dicarboxylic acids from unsatd. fatty acids, resp.; furthermore, 2,2-dimethyl succinic acid [597-43-3] and 2,2-dimethyl glutaric acid [681-57-2] were produced from b-carotene.Except for chemicals metioned above, 69-72-7 and 544-63-8 are also used. .

Asymmetric synthesis of the C(10)-C(16) segment of the bryostatins

Asymmetric synthesis of the C(10)-C(16) segment of the bryostatins. Lampe, Thomas F. J.; Hoffmann, H. M. R. (Dep. Org. Chem., Univ. Hannover, Hannover 30167, Germany). Tetrahedron Letters, 37(43), 7695-7698 (English) 1996 Elsevier. CODEN: TELEAY. ISSN: 0040-4039. DOCUMENT TYPE: Journal CA Section: 26 (Biomolecules and Their Synthetic Analogs) Section cross-reference(s): 33 The C(10)-C(16) segment I [R = Si(CHMe2)3, X = CHCH2OSiPh2CMe3] of the bryostatins has been synthesized (12 steps, 15% overall yield) from C-glycoside deriv. I (R = Ac, X = O). A cyanohydrin based strategy was also developed for coupling of I with a C(1)-C(9) segment model compd..Except for chemicals metioned above, 681-57-2 is also used. .