96553-70-7Relevant articles and documents
Selective functional transformation of 1,2-diols via organophosphorus reagents
Pirat, Jean-Luc,Carteron, Michel,Maggio, Annie-Francoise,Bot, Stephanie,Cristau, Henri-Jean
, p. 609 - 612 (2007/10/03)
A new synthesis of 1,3,2λ5-dioxaphospholanes was realized by direct reaction of dibromotriphenylphosphorane with 1,2-diols. Ring opening studies were performed with or without electrophilic activation (Lewis acids or hydrogen bonding) in order to substitute selectively one of the hydroxy function.
THE SYNTHETIC UTILITY OF DIOXYPHOSPHORANES IN ORGANIC SYNTHESIS
Robinson, Philip L.,Kelly, Jeffery W.,Evans, Slayton A.
, p. 15 - 24 (2007/10/02)
Diethoxytriphenylphosphorane, DTPP, prepared by reaction of triphenylphosphine and diethyl peroxide, is a "hydrolytically active" dioxyphosphorane which promotes mild and efficient cyclodehydration of diols to cyclic ethers in neutral media.Simple 1,2-, 1,4-, and 1,5-diols afford good yields of the cyclic ethers but 1,3-propanediol and 1,6-hexanediol give mainly 3-ethoxy-1-propanol and 6-ethoxy-1-hexanol, respectively, with DTPP.Tri- and tetra-substituted 1,2-diols afford the relatively stable 1,3,2-dioxaphospholanes in the presence of DTPP and the reaction conditions dictate whether epoxides, ketones, or allylic alcohols are obtained.
Diethoxytriphenylphosphorane: A Mild, Regioselective Cyclodehydrating Reagent for Conversion of Diols to Cyclic Ethers. Stereochemistry, Synthetic Utility, and Scope
Robinson, Philip L.,Barry, Carey N.,Kelly, Jeffery W.,Evans, Slayton A.
, p. 5210 - 5219 (2007/10/02)
Diethoxytriphenylphosphorane, Ph3P(OEt)2, prepared by reaction of triphenylphosphine and diethyl peroxide, is a "hydrolytically active" dioxyphosphorane which promotes mild cyclodehydration (40-110 deg C) of diols to cyclic ethers in neutral media.The regioselectivity in the closure of (S)-(+)-propane-1,2-diol and (R)-(-)-pentane-1,4-diol with Ph3P(OEt)2 is high (81-82 percent) while the cyclodehydration of (S)-(+)-phenylethane-1,2-diol gives racemized (+/-)-styrene oxide.Simple 1,2-, 1,4-, and 1,5-diols afford good yields of the cyclic ethers but 1,3-propanediol and 1,6-hexanediol give mainly 3-ethoxy-1-propanol and 6-ethoxy-1-hexanol, respectively with Ph3P(OEt)2.Tri- and tetra-substituted 1,2-diols afford the relatively stable 1,3,2-dioxaphospholanes (or ?-dioxyphosphoranes) in the presence of Ph3P(OEt)2, and, depending on conditions, the 1,3,2-dioxaphospholanes are selectively converted to epoxides, ketones or allylic alcohols.The carbonyl compounds arise from 1,2-hydride and 1,2-methyl migrations; the allylic alcohols are derived from thermolytic eliminations. trans-1,2-Cyclohexanediols afford essentially quantitative yields (>95 percent) of the cyclohexene oxides while cis-1,2-cyclohexanediol gives the stable 1,3,2-dioxaphospholane with Ph3P(OEt)2 which decomposes under thermal conditions to cyclohexanone (90 percent).Ph3P(OEt)2 is extremely useful for conversion of "sensitive" 1,2-diols to acidic and /or thermally labile epoxides as demonstrated by the quantitative conversion of 9,10-dihydro-trans-9,10-phenanthrenediol to 9,10-dihydrophenanthrene oxide and 2α,10-pinanediol to 2α,10-epoxypinane.
