A facile procedure for acetalization under aprotic conditions

The use of anhydrous CeCl3 as a recyclable and selective catalyst for the acetalization of aldehydes and ketones

“…2 Because of the versatility and usefulness of acetals in organic synthesis, several methods for the protection [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and the selective, mild deprotection 21 of aldehydes and ketones have been described. The classical procedure for protection involves the Lewis [3][4][5][6][7][8][9][10][11][12][13][14][15] or protic acid-catalyzed [16][17][18][19][20] reaction of a carbonyl compound with a large excess of an alcohol in the presence of a water scavenger. Among the employed Lewis acids are metal triflates, [3][4][5][6][7][8] 19 and silica-supported HClO 4 20 have been used as protic acids.…”

Stereoisomer libraries: Total synthesis of all 16 stereoisomers of the pine sawfly sex pheromone by a fluorous mixture-synthesis approach

“…The syntheses of the six building blocks (all four isomers of 2-methyl-1,3-butane diol 2 and the two enantiomers of phenylsulfonyl tetrazole 3) were straightforward and are summarized in Materials and Methods. In the last step of the premix stage, each diol 2 was reacted individually with a different fluorous p-methoxybenzaldehyde derivative 10a-10d by the method of Noyori and coworkers (17) to code its configuration to the fluoroalkyl group in the tagged acetals 11a-11d (Fig. 3).…”

The case for noncompetitive cyclizative options during attempted expedient construction of the core ring system of CP-263,114

“…18 Introduction of the diester-containing side chain was accomplished at this stage by stirring 8 with dimethyl (E)-hexenedioate under conventional Heck conditions. 19 Application of this difunctional reagent, directly available from the palladiumcatalyzed dimerization of methyl acrylate, 20 provided the key triester 4.…”