Silafunctional compounds in organic synthesis. 30. Intramolecular hydrosilation of alkenyl alcohols: A new approach to the regioselective synthesis of 1,2- and 1,3-diols
作者:Kohei Tamao、Tetsu Tanaka、Takashi Nakajima、Ritsuo Sumiya、Hitoshi Arai、Yoshihiko Ito
DOI:10.1016/s0040-4039(00)84800-5
日期:1986.1
Intramolecular hydrosilation of allyl and homoallyl alcohols and the subsequent oxidative cleavage of the resultant carbon—silicon bond have provided a new approach to the regio-controlled synthesis of 1,2- and/or 1,3-diols.
The reaction of trialkylvinylborates with aldehydes as applied to syntheses of 1,3-alkanediols, 1-chloro-3-heptanol and a cyclopropane derivative
作者:K. Utimoto、K. Uchida、H. Nozaki
DOI:10.1016/0040-4020(77)80382-7
日期:1977.1
R2BCHR-CH2-CH(OLi)R' (2) or its borate form (3). Oxidation of the adducts with alkaline hydrogen peroxide gives ca. 1:1 mixture of diastereomeric 1,3-alkanediols in good yields. On the other hand, the reaction of BrMg[R3BCHCH2] with R'CHO affords less satisfactory results. Successive treatment of 2 (R = n-Bu, R' = H) with PCl5 and alkaline H2O2 gives HOCHBu-CH2-CH2Cl (6). Treatment of Et2BCHEt-CH2-CHCl-Ph
THE REACTION OF LITHIUM TRIALKYLVINYLBORATES AND ALDEHYDES AS APPLIED TO THE SYNTHESIS OF 1,3-DIOLS, γ-CHLOROALCOHOL, AND CYCLOPROPANE
作者:Kiitiro Utimoto、Keiichiro Uchida、Hitosi Nozaki
DOI:10.1246/cl.1974.1493
日期:1974.12.5
Reaction of lithium trialkylvinylborates with aldehydes gives non-isolable boron compounds, 1,2-oxaborolane-bases borates (II) whose oxidative work-up furnishes 1,3-diols (III) smoothly. Successive treatment of a cyclic borate with phosphorus pentachloride and aqueous alkali provides a cyclopropane.
Direct enantioselective synthesis of syn-1,3-diols by the reaction of aldehydes with enol silyl ethers in the presence of a chiral borane complex. Successive asymmetric aldol reaction and asymmetric reduction with one promoter
作者:Yuichi Kaneko、Takao Matsuo、Syun-ichi Kiyooka
DOI:10.1016/s0040-4039(00)73125-x
日期:1994.6
A stoichiometric amount of the chiral borane 1 turned out to successively promote the asymmetric aldolreaction of aldehydes with enol silyl ethers and the following asymmetric reduction in one pot to afford syn-1,3-diols with high enantioselectivity.
BCl<sub>3</sub>- and TiCl<sub>4</sub>-Mediated Reductions of β-Hydroxy Ketones
作者:Christopher R. Sarko、Scott E. Collibee、Allison L. Knorr、Marcello DiMare
DOI:10.1021/jo951549x
日期:1996.1.1
Syn-selective reduction protocols for beta-hydroxy ketones are described exploiting the intermediacy of titanium and boron chelates derived from TiCl4 and BCl3, respectively, Reductions are conducted at -78 degrees C in CH2Cl2 using a wide range of CH2Cl2-soluble reducing agents, Added acid-scavenging agents are detrimental to reaction selectivity, An A((1,3))-like interaction involving the stereocenter responsible for asymmetric induction provides conformational biasing of the intermediate chelates necessary for high diastereoselectivity.