Control of skeletal connectivity in indium promoted reactions: 1,2-Additions and Cope rearrangements en route to lactol formation

Indium promoted coupling of propargyl aldehydes with allyl halides has resulted in the synthesis of propargyl alcohols under aqueous and organic conditions. Oxy-Cope rearrangement of 4-hydroxy-1-ene-5-ynes followed by a secondary addition step under highly basic conditions has led to the formation of lactol.