摘要
The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.
The novel 19 nor l α ,25 dihydroxy vitamin D 3 analogues possessing an ethyl at the 2 position(4 and 5), were synthesized by coupling 25 hydroxy Windaus Grundmann ketone derivative 20 with A ring synthons(15 and 19) respectively. The enantioselective synthesis of substituted bicyclic hexanes structure A ring synthons, started from all cis 3,5 dihydroxy 4 ethyl 1 (methoxycarbonyl)cyclohexane via lipase catalyzd asymmetrization, was demonstrated.
