A practical and scaleable synthesis of 1R,5S-bicyclo[3.1.0 ]hexan-2-one : The development of a catalytic lithium 2,2,6,6-tetramethylpiperidide (LTMP) mediated intramolecular cyclopropanation of (R)-1,2 -epoxyhex-5-ene

An efficient synthesis of 1R,5S-bicyclo[3.1.0]hexan-2-one from (R)-1,2-epoxyhex-5-ene is described. Development of a catalytic intramolecular cyclopropanation of (R)-1,2-epoxyhex-5-ene gives the key homochiral bicycle[3.1.0]hexan-1-ol, which is then oxidized to the desired ketone. This process has been successfully demonstrated on a multi-kilogram scale.