Enantioselective syntheses of orthogonally protected tricarballylic acid esters
摘要:
3(S) and 3(R)-Benzyloxycarbonyl-pentanedioic acid mono-tert-butyl esters (6) were obtained as enantiopure orthogonally protected tricarballylic acid (TCA) esters. These were synthesised by alkylation of the sodium enolate derived from chiral but-3-enoyloxazolidinone imides (3) with tert-butyl bromoacetate; following the hydrolysis to remove the chiral auxiliary, benzyl esterification afforded the 2-allyl succinic acid diesters (4) that were converted to protected TCA esters after oxidation of the double bond. (C) 2000 Elsevier Science Ltd. All rights reserved.
Enantioselective syntheses of orthogonally protected tricarballylic acid esters
摘要:
3(S) and 3(R)-Benzyloxycarbonyl-pentanedioic acid mono-tert-butyl esters (6) were obtained as enantiopure orthogonally protected tricarballylic acid (TCA) esters. These were synthesised by alkylation of the sodium enolate derived from chiral but-3-enoyloxazolidinone imides (3) with tert-butyl bromoacetate; following the hydrolysis to remove the chiral auxiliary, benzyl esterification afforded the 2-allyl succinic acid diesters (4) that were converted to protected TCA esters after oxidation of the double bond. (C) 2000 Elsevier Science Ltd. All rights reserved.
A series, of cyclic pseudopeptides were synthesized containing the sequence -Trp-PhC-(D)-PhePsiCH(2)NH-, the terminal ends of which were bound to 2-carboxy succinate or enantiomerically enriched tricarballylic acid to give the final cyclic structures. These two molecules and their subsequent derivatives were screened for h-NK2 receptor binding and functional antagonist activity on the rabbit urinary bladder. (C) 2002 Published by Elsevier Science Ltd.
Enantioselective syntheses of orthogonally protected tricarballylic acid esters
3(S) and 3(R)-Benzyloxycarbonyl-pentanedioic acid mono-tert-butyl esters (6) were obtained as enantiopure orthogonally protected tricarballylic acid (TCA) esters. These were synthesised by alkylation of the sodium enolate derived from chiral but-3-enoyloxazolidinone imides (3) with tert-butyl bromoacetate; following the hydrolysis to remove the chiral auxiliary, benzyl esterification afforded the 2-allyl succinic acid diesters (4) that were converted to protected TCA esters after oxidation of the double bond. (C) 2000 Elsevier Science Ltd. All rights reserved.