SCOOPY-Reaktionen : Stereoselektivität der Allylalkohol-Synthese via Betain-Ylide
The stereoselectivity of the SCOOPY reaction, in which allyl alc. derivs. are prepd. by reaction of betaine ylides with carbonyl compds., was investigated by the synthesis of 1-hydroxy-2-octene (I), and 1-hydroxymethyl-2-octene (II) from Ph3P+-CH2 and Ph3P+-CHMe, resp., using HCHO and octanal. Treatment of III with HCHO in the presence of LiBr followed by treatment with n-C5H11CHO gave 10% I having a 97:3 cis-trans ratio. A 36% yield of II with a 30:70 cis-trans ratio was obtained by treating III with n-C5H11CHO and then with HCHO. Treatment of Ph3P+-CHMe with n-C5H11CHO and then with HCHO gave 71% II with a 99.3:0.7 cis-trans ratio, while treatment with HCHO and then with n-C5H11CHO gave 48% II with a 36:64 ratio. [on SciFinder (R)]
Physical Organic Chemistry
Org. Chem. Inst.,Univ. Heidelberg,Heidelberg,Fed. Rep. Ger.
written in German.
33965-54-7P; 33965-55-8P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 1754-88-7; 3487-44-3; 19493-09-5; 19493-10-8 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with caproaldehyde and formaldehyde); 66-25-1 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with formaldehyde and phosphorus ylides); 50-00-0 Role: RCT (Reactant), RACT (Reactant or reagent) (with phosphorus ylides and caproaldehyde)
Record created on 2006-03-03, modified on 2016-08-08