SYNTHESIS OF POTENTIAL INHIBITORS OF ETHYLENE BIOSYNTHESIS - THE DIASTEREOISOMERS OF 1-AMINO-2-BROMOCYCLOPROPANECARBOXYLIC ACID

The preparation of the diastereoisomers of 1-amino-2-bromocyclopropane carboxylic acid is described using the methyl SSR)-2-oxo-3-oxabicyclo[ 3.1.0]hexane-1-carboxylate 5 as starting material. The key step is the oxidation of 9 with subsequent radical introduction of bromine accord ing to the Barton procedure. The 2-bromo-cyclopropanecarboxylates cis- ll and trans-11 were obtained as diastereoisomer mixture in a ratio of 3:1. They were converted into cis- and trans-esters 12 and the acids 13.