Magnesium mediated carbometallation of propargyl alcohols: direct routes to dihydroxydienes and enediyne alcohols

The addition of vinyl and alkynyl Grignard reagents to propargyl alcohols for the direct synthesis of dihydroxydienes and enediyne alcohols from a one pot reaction is described. These products arise from the putative magnesium chelate intermediate 2 upon reaction with the appropriate electrophile.