Selective syntheses with organometallics. Part XI. An efficient synthesis of a,b-unsaturated aldehydes by a four-carbon unit extension of Grignard reagents

Cloux, RolandSchlosser, Manfred2006-03-032006-03-032006-03-03198410.1002/hlca.19840670607https://infoscience.epfl.ch/handle/20.500.14299/226821Oxirane I, prepd. by epoxidn. of (EtO)2CHCH2CH:CH2, reacted with Grignard reagents in the presence of catalytic CuBr to give 78-92% b-hydroxyacetals (EtO)2CHCH2CHR1OH [II; R1 = CH2CMe3, CH2CHMeEt, pentyl, CH2CH2CMe:CH2, CH2Ph, CH2CH2Ph, (CH2)7OR2; R2 = tetrahydropyranyl, SiMe3], which gave enals HCOCH:CHR1 in 50-85% yield on hydrolysis. Careful hydrolysis of II (R1 = CH2CMe3) gave HCOCH2CHR1OH, which formed H2C:CHCH2CHR1OH on Wittig reaction or dimerized to form 1,3-dioxane III. [on SciFinder (R)]Grignard's reagents Role: RCT (Reactant)RACT (Reactant or reagent) (reaction ofwith oxirane deriv.b-hydroxyacetal by); Aldehydes Role: SPN (Synthetic preparation)PREP (Preparation) (ab-unsatd.prepn. offrom oxirane deriv. and Grignard reagenaldehyde unsatd; hydroxyacetal hydrolysis dehydration; oxirane diethoxyethyl Grignard; Grignard diethoxyethyloxiraneSelective syntheses with organometallics. Part XI. An efficient synthesis of a,b-unsaturated aldehydes by a four-carbon unit extension of Grignard reagentstext::journal::journal article::research article