Highly cis-selective Wittig reactions employing a-heterosubstituted ylides
1-Alkenyl chlorides, bromides or iodides, e.g., cis-1-chloro-1-octene, can be obtained with very high cis selectivities by Wittig reactions with a-chloro, a-bromo and a-iodo ylides derived from (2-MeOCH2C6H4)3P. The corresponding a-methoxy substituted ylide produces enol ethers with remarkably high cis/trans ratios. Pd(II)-catalyzed coupling of (Z)-1-iodo-1-heptene with Et acrylate affords Et (2E,4Z)-2,4-decadienoate, the Bartlett pear fragrance, in almost quant. yield. [on SciFinder (R)]
1993
34
12
1925
1928
CAN 119:94920
23-3
Aliphatic Compounds
Inst. Chim. Org.,Univ. Lausanne,Lausanne,Switz.
Journal
written in English.
97-96-1; 100-52-7 (Benzaldehyde); 111-71-7 (Heptanal); 123-11-5 (p-Methoxybenzaldehyde); 455-19-6; 630-19-3; 2094-74-8 (1-Adamantanecarboxaldehyde); 6728-26-3 Role: RCT (Reactant), RACT (Reactant or reagent) (Wittig reaction of, with ylides); 63318-29-6 Role: RCT (Reactant), RACT (Reactant or reagent) (coupling reaction of, with Et acrylate); 140-88-5 (Ethyl acrylate) Role: RCT (Reactant), RACT (Reactant or reagent) (coupling reaction of, with iodoheptene); 149065-79-2P; 149065-80-5P; 149065-81-6P; 149065-82-7P; 149065-83-8P Role: RCT (Reactant), PREP (Preparation), RACT (Reactant or reagent) (generation and Wittig reaction of, with aldehydes); 149065-92-9P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. and ylide formation from); 588-73-8P; 3025-30-7P; 4604-28-8P; 14371-19-8P; 18314-61-9P; 18684-79-2P; 20405-77-0P; 20405-78-1P; 32814-16-7P; 32814-17-8P; 36024-31-4P; 42843-49-2P; 52356-93-1P; 57918-63-5P; 62469-75-4P; 64531-23-3P; 139913-95-4P; 149065-84-9P; 149065-85-0P; 149065-86-1P; 149065-87-2P; 149065-88-3P; 149065-89-4P; 149065-90-7P; 149065-91-8P Role: SPN (Synthetic preparation), PREP (Preparation) (prepn. of); 124629-80-7 Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with chloroiodomethane); 593-71-5 (Chloroiodomethane) Role: RCT (Reactant), RACT (Reactant or reagent) (reaction of, with tris(methoxymethoxyphenyl)phosphine)
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