Development of Synthetic Routes to <scp>d</scp>,<scp>l</scp>-α-Tocopherol (Vitamin E) from Biologically Produced Geranylgeraniol
作者:John A. Hyatt、Gregg S. Kottas、Janet Effler
DOI:10.1021/op020216g
日期:2002.11.1
isophytol as a side-chain synthon for producing d,l-α-tocopherol. Two routes were studied, both of which begin with allylic epoxidation followed by olefin hydrogenation to give epoxyphytol. Epoxyphytol can be reduced with Red-Al to provide phytan-1,3-diol which upon acid-catalyzed condensation with trimethylhydroquinone gives vitaminE in fair yield. In a higher-yielding process, epoxyphytol was deoxygenated
探索了使用生物衍生的二萜醇香叶基香叶醇作为基于石油化学的异植醇的替代品,作为用于生产 d,l-α-生育酚的侧链合成子。研究了两条路线,均以烯丙基环氧化开始,然后烯烃氢化得到环氧植醇。环氧植物醇可以用 Red-Al 还原以提供植烷-1,3-二醇,其在酸催化下与三甲基氢醌缩合以合理的收率生成维生素 E。在更高产率的过程中,环氧植醇与三氧化甲基铼/三苯基膦脱氧,生成植醇和异植醇的混合物(来自香叶基香叶醇的产率 > 90%)。这种混合物可以作为异植醇的“插件”替代品,用于目前实施的维生素 E 化学的最后一步。
Regio-and stereo-selection reaction of 1,3-dialkyl-substituted allyl anions with aldehydes viaη<sup>3</sup>-allyltitanium compounds
作者:Yuichi Kobayashi、Kensuke Umeyama、Fumie Sato
DOI:10.1039/c39840000621
日期:——
The Regio-and stereo-chemistry in reaction of 1,3-dialkyl-substitutedallylanions with aldehydes is controlled viaη3-allyltitanium compounds, thus providing a simple method for preparation of cycloalkanes having a 1- hydroxyalkyl side chain.
Rh(I)-catalyzed cleavage of unactivated CO bonds Carbonylative rearrangement reactions of allenyl ethers to 2-carboalkoxy-1,3-dienes
作者:Paul A Wender、Nicole M Deschamps、Robert Sun
DOI:10.1139/v05-085
日期:2005.6.1
The initial examples of a Rh(I)-catalyzed carbonylative rearrangement reaction of allenyl ethers are described. The key reaction proceeds under remarkably mild conditions to provide good to excellent yields of 2-carboalkoxy-1,3-dienes.Key words: carbonylative rearrangement, C-O cleavage, σ bond activation, rhodium catalysis, allenyl ethers.
Regio- and stereoselective hydrosulfonylation of conjugated dienes via (.pi.-allyl)palladium complex
作者:Yoshinao Tamaru、Yoshimi Yamada、Masahiro Kagotani、Hirofumi Ochiai、Eiji Nakajo、Ryoshu Suzuki、Zenichi Yoshida
DOI:10.1021/jo00172a043
日期:1983.12
A highly enantioselective approach to functionalized [4.n.0] bicyclic compounds
作者:Juan C Carretero、José L García Ruano、Luisa M Martín Cabrejas
DOI:10.1016/s0040-4039(00)78213-x
日期:1994.8
The Diels-Alder reaction of benzyl, methyl (S)-2-(p-tolylsulfinyl) maleate with several 1-vinylcycloalkenes, catalyzed by TiCl4, occurred with complete regio and stereoselectivity. The regioselectivity of the sulfinyl elimination from the adducts, as well as;the stereoselectivity of the epoxidation and the hydroboration of the resulting [4.n.0] bicyclic compounds, increase with the size of the second ring.