Synthesis of the Marine Compound (2<i>R</i>,5<i>Z</i>,9<i>Z</i>)-2-Methoxyhexacosa-5,9-dienoic Acid via a Lipase-Catalyzed Resolution and a Novel O-Alkylation Protocol
作者:Subrata Chattopadhyay、Bheemashankar A. Kulkarni、Anubha Sharma、Sunita Gamre
DOI:10.1055/s-2004-815963
日期:——
been synthesized by a facile route starting from 4-pentyn-1-ol. The enantioselectivity was attained by a strategy involving a lipase-catalyzedacetylation of a solid-phase immobilized long chain α-hydroxyacid. Another important feature of the synthesis was the formulation of an efficient HgO-catalyzed O-methylation of the α-hydroxyacids which proceeded without any racemization. The alkylation protocol
Two new long-chain ceramides, trametenamides A (1) and B (2), were isolated from the methanolic extract of the fruiting body of the fungus Trametes menziesii. The structures were elucidated by spectroscopic analyses and chemical transformations, and the absolute stereochemistry of trametenamide B (2) was determined by stereoselective total synthesis of four possible diastereomers. The acetyl derivative
A medicinal composition comprising at least one compound represented by general formula (A), specifically a myeloid cell growth promoter, a radiation damage protective and a thrombocytopenia remedy, wherein R represents (α), (R₂ being H or OH, and X being an integer of 0 to 26) or -(CH₂)₇CH=CH(CH₂)₇CH₃; R₁ represents a substituent selected from the group consisting of -CH₂(CH₂)YCH₃, -CH(OH)(CH₂)YCH₃, -CH(OH)(CH₂)YCH(CH₃)₂ and -CH=CH(CH₂)YCH₃; and Y represents an integer of 5 to 17.
一种药物组合物,包含至少一种由通式(A)代表的化合物,特别是一种髓系细胞生长促进剂、一种辐射损伤保护剂和一种血小板减少治疗剂,其中 R 代表(α),(R₂为 H 或 OH,X 为 0 至 26 的整数)或-(CH₂)₇CH=CH(CH₂)₇CH₃;R₁ 代表选自以下组成的组的取代基:-CH₂(CH₂)YCH₃、-CH(OH)(CH₂)YCH₃、-CH(OH)(CH₂)YCH(CH₃)₂ 和 -CH=CH(CH₂)YCH₃;以及 Y 代表 5 至 17 的整数。
Synthesis of racemic and each enantiomer of 3-methylnonacosanol, a new plant growth regulator from Lowsonia inermis
作者:Bheemashankar A Kulkarni、Sivaraman Sankaranarayanan、Ayalur S Subbaraman、Subrata Chattopadhyay
DOI:10.1016/s0957-4166(99)00150-0
日期:1999.4
An efficient synthesis of the title compound I in racemic and enantiomeric forms has been developed starting from 10-undecenoic acid. For the enantiomeric synthesis, a lipase catalyzed acylation strategy was employed to prepare the required methyl branched chiron which was subsequently derivatized to give the enantiomers of I. The plant growth regulatory (PGR) assay of I, carried out with hypocotyl cuttings of French beans (Phaseolus vulgaris L.) in Steinberg's nutrient medium revealed appreciable activity at a concentration of 2.5 ppm. The PGR activities of the compound both in racemic and enantiomeric forms were better than 1-triacontanol, the enantiomer, (S)-I being the best test candidate. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
Unsaturated acids and macrocyclic lactones Communication 11. Total syntheses of cis-8-hexadecenoic, cis-11-hexadecenoic (palmitovaccenic), cis-7-octadecenoic, and cis-9-hexacosenoic acids
作者:L. D. Bergel'son、V. A. Vaver、L. I. Barsukov、M. M. Shemyakin