Ann E. DeCamp

Stereocontrolled addition of propionate homoenolate equivalents to chiral α-amino aldehydes

Abstract A highly efficient route is presented for preparation of the medicinally important hydroxyester and lactone intermediates 1 and 2 from chiral α-amino aldehydes via homoenolate methodology. Several reaction variables were found to influence the ratio of chelation controlled versus Felkin-Ahn products.

Preparation of 2-aryl- and 2-alkenyl-substituted carbapenems under mild suzuki cross-coupling conditions

Abstract An extraordinarily mild procedure for the synthesis of 2-aryl- and 2-alkenyl-substituted carbapenems via palladium-catalyzed coupling of a vinyl triflate with aryl or vinyl boronic acids is described. A major advantage of this procedure is the use of nontoxic boronic acid intermediates in place of highly toxic organostannane compounds which are used in the corresponding Stille cross-coupling reactions.

Efficient synthesis of carbapenems via the oxalimide cyclization. Manipulation of protecting groups at the oxalimide stage

Abstract An efficient synthesis of the carbepenem nucleus from TBDMS protected acetoxyazetidinone via oxalimide cyclization technology is demonstrated. A key step is desilylation of the oxalimide intermediate. Access to a variety of protecting group schemes is demonstrated.

Stereocontrolled addition of chiral, non-racemic amide homoenolates to t-Boc-(S)-phenylalaninal

The reaction of chiral indanolamide homoenolates 4a and 4c with t-Boc-(S)-phenylalaninal 3 exclusively gave the non-chelation product in contrast to the propionate ester homoenolate 7c, 1a which gives predominantly the chelation controlled product. However, the reaction of simple achiral amide homoenolates 7a and 7b with 3 was nonselective.