A Convenient Method for the Synthesis of Allenoates from 4-HydroxyaIk-2-ynoates with PPh3

摘要

Structurally unique allenyl substances are found in nature and play important biological and chemical roles. Allenes become versatile building blocks in synthetic chemistry, the inherent instability associated with the cumulated double bond having been widely exploited for synthetic purposes. Recently allene moieties have been utilized as useful substrates for a variety of chemical transformations including many transition metal catalysis. As a result, considerable attentions have been paid to develop synthetic methodologies for the compounds containing allenyl functionalities. In particular, allenoates have considered as an attractive substrate class showing diverse reactivity for Lewis base-catalyzed reactions with various electrophiles. However, majority of known methods for the synthesis of allenoates 2 are utilized the Wittig reaction between phosphonium ylide and ketene from acyl chloride with base.