Wittig olefination: An efficient route for the preparation of allyl vinyl ethers - precursors for the Claisen rearrangement
作者:Mukund G. Kulkarni、Dhananjay S. Pendharkar、Ravindra M. Rasne
DOI:10.1016/s0040-4039(97)00057-9
日期:1997.2
A convenient procedure has been described for the preparation of allyl vinyl ethers-the precursors for the Claisen rearrangement
已经描述了用于制备烯丙基乙烯基醚-克莱森重排的前体的方便程序。
The wittig rearrangement as a practical method for aldehyde synthesis
作者:Manfred Schlosser、Sven Strunk
DOI:10.1016/s0040-4020(01)80095-8
日期:1989.1
If the rearrangement of metalated allyl ethers 2 (or 4) is accomplished in the presence of potassium tert-butoxide, primary alkyl groups preferentially migrate to the unsubstituted allylic terminus (γ-position). Enolates 7 and 1-vinylalcoholates 6 (by alkyl migration to the α-position, adjacent to the oxygen atom) are produced in an approximate ratio of 9:1. Because of the endo-configuration of their
Photochemical Reaction Cascade from <i>O</i>-Pent-4-enyl-Substituted Salicylates to Complex Multifunctional Scaffolds
作者:Andreas Zech、Thorsten Bach
DOI:10.1021/acs.joc.8b00238
日期:2018.3.16
The arene ring of the title compounds is cleaved by a reaction cascade which is initiated by an intramolecular ortho photocycloaddition reaction. Tricyclic products were obtained in a highly regio- and diastereoselective fashion via a cyclooctatriene intermediate. The facial diastereoselectivity exerted by a stereogenic center in the tether is moderate to good (dr = 65/35 to 82/18). Yields were acceptable
hexodialdo-1,5-pyranosides were reacted with four Grignard C1 reagents: methoxymethyl-, allyloxymethyl-, benzyloxymethyl, and dimethylphenylsilylmethyl-magnesium chlorides. Two stereoisomeric heptoses were obtained in each case in a good yield. The methyl alloside-derived heptosides were accompanied by C-5 inverted products. The addition of Grignardreagents to aldehydes 5–8 has been discussed in terms
studies using a simple diketopiperazine derivative. As a result, allyloxymethyl (Allom) group was the most suitable protecting group, which tolerated Nicolaou’s sulfenylation conditions, and was easily cleavable under the mild conditions using Pd(PPh3)4 and N,N-dimethylbarbituric acid leaving methylthioethers intact. The general utility of Allom group for protection of amides was studied using simple