An efficient SbCl3-metal system for allylation, reduction and acetalization of aldehydes
作者:- Bo Wang Wei、Shi Li-Lan、Huang Yao-Zeng
DOI:10.1016/s0040-4020(01)85467-3
日期:1990.1
allylatlon of aldehydes with allylic halides at room temperature to give high yields of the corresponding homoallylic alcohols with high regio- and chemoselectivity. SbCl3-Al or SbCl3-Zn in DMF-H2O was found to be an efficient reduction system for conversion of aldehydes to alcohols at room temperature in excellent yields. While alcohol was used as solvent instead of DMF-H2o, the acetalization product was
Acetonyltriphenylphosphonium Bromide and Its Polymer-Supported Analogues as Catalysts for the Protection of Carbonyl Compounds as Acetals or Thioacetals
Abstract Both acetonyltriphenylphosphonium bromide (ATPB) and poly-p-styryldiphenylacetonylphosphonium bromide (PATPB) are excellent catalysts in the protection of aldehydes as acetals or thioacetals. In general, ATPB is highly selective as ketones do not give good yields of ketals with this catalyst.
Visible-Light-Induced Acetalization of Aldehydes with Alcohols
作者:Hong Yi、Linbin Niu、Shengchun Wang、Tianyi Liu、Atul K. Singh、Aiwen Lei
DOI:10.1021/acs.orglett.6b03403
日期:2017.1.6
have achieved a simple and general method for acetalization of aldehydes by means of a photochemical reaction under low-energy visible light irradiation. A broad range of aromatic, heteroaromatic, and aliphatic aldehydes have been protected under neutral conditions in good to excellent yields using a catalytic amount of Eosin Y as the photocatalyst. Our visible light mediated acetalization strategies are
give (diiodomethylene)cycloalkanes. The diiodomethylene products are also obtained by iodine atom-transfer-type cyclization of ω-iodo-1-alkynes, using 1-iodo-1-hexyne as an external iodine atom source. Bromine atom-transfer and proton-transfer cyclization proceed as well by employing 1-bromo-1-octyne and 1-octyne, respectively. These reactions are proposed to proceed through a carbenoid-chain process
Synthesis of optically active cyclohexenol derivatives via enzyme catalyzed ester hydrolysis of 4-acetoxy-3-methyl-2-cyclohexenone
作者:Magnus Polla、Torbjörn Frejd
DOI:10.1016/s0040-4020(01)86539-x
日期:1991.7
The opticallyactive cyclohexenol derivatives 9a–9d, and 10a–10c are synthesized from (−)-6, which is obtained by enzymatic esterhydrolysis of racemic 8. Attempts towards the synthesis of the taxane skeleton are described.