Stereoselective Total Synthesis of (+)-Brevipolide H from d -Galactal

An efficient and concise synthesis of cytotoxic 5,6-dihydro?-pyrone (+)-brevipolide H has been accomplished in 12 long linear steps in 8.65% overall yield from readily available chiral synthons, D-ga-lactal and ethyl L-lactate. The features of this synthesis are highly diastereoselective Simmons-Smith cyclopropanation and carbohydrate based chiron approach to rapid access to key 5,6-dihydro-?-pyrone skeleton.

Automated summary

An efficient and concise synthesis of cytotoxic 5,6-dihydro?-pyrone (+)-brevipolide H has been achieved through 12 linear steps with an overall yield of 8.65% from readily available chiral synthons, D-galactal and ethyl L-lactate. The key features of this synthesis include highly diastereoselective Simmons-Smith cyclopropanation and a carbohydrate-based chiron approach for rapid access to the key 5,6-dihydro-?-pyrone skeleton.