Enzymatic hydrolysis of 2,6-diacetoxybicyclo[3.3.1]nonane and 2,6-diacetoxy-3,3,7,7-tetramethylbicyclo[3.3.1]nonane; a facile synthesis of the optically active chiral subunit for crown ethers
Hydrolysis of 2,6-diacetoxybicyclo[3.3.1]nonane (5) using lipase from Candida cylindracea gave (+)-(1S,2R,5S,6R)-(4)[81% enantiomeric excess (e.e.)] and (–)-(1R,2S,5R,6S)-(5)[95% e.e.], and pig liver esterase-catalysed hydrolysis of 2,6-diacetoxy-3,3,7,7-tetramethylbicyclo[3.3.1]nonane (9) gave (–)-(1S,2R,5S,6R)-(7)(96% e.e.) and (+)-(1R,2S,5R,6S)-(9)(86% e.e.); the enantiomer recognition behaviour of the crown ethers (–)-(11) and (+)-(12) prepared from (–)-(3) and (+)-(7), respectively, has been examined.