Stereocontrolled synthesis of all-syn 3,4-disubstituted l-prolines: studies of the reductive rearrangement of unactivated tertiary allylic alcohols

We describe a stereocontrolled method that converts tertiary allylic alcohols in pyrrolidine-2-carboxylic acid derivatives prepared from 3-(S)-hydroxy-l-proline to all-syn 3,4-disubstituted l-prolines. A study of various parameters to optimize the reductive rearrangement of tertiary allylic alcohols to tetrasubstituted olefins was conducted.