Stereospecific Synthesis of Allenes from Propargylic Alcohols

Significance

A direct straightforward route to the stereospecific synthesis of allenes from propargylic alcohols has been disclosed. Hereby, two complementary sets of conditions have been identified which, together, allow the preparation of dialkyl-, diaryl- and aryl-,alkyl-substituted allenes. The reaction proceeds via syn-addition of the Schwartz reagent to the triple bond of the propargylic alcohol. Subsequent syn-elimination leads to the desired allenes.