An Entry to Functionalized 2,8-Ethanonoradamantane Derivatives

Stereoselective preparation of key intermediates for the synthesis of iso-, neuro- and phyto-prostane family members: inaugural asymmetric synthesis of 17-E2c-dihomo- and 17-F2c-dihomo-isoprostanes

A practical methodology for the synthesis of key intermediates for isoprostane, neuroprostane and dihomo-isoprostane preparation has been described. The key strategy involved a three stage C-12 stereocenter inversion of the configuration of a Corey lactone, commercially available in an enantiopure form. The key intermediate was then used to prepare 17-E2c-dihomo-isoprostane and 17-F2c-dihomo-isoprostane.

Alternative Access to Functionalized 2,8-Ethanonoradamantane Derivatives

7a-(Methoxycarbonyl)-N-methyl-1,3a,5,6,7,7a-hexahydro-4H-1,4,6-(epiethane[1,1,2]triyl)indene-4,9-dicarboximide has been prepared through a modification of a previous synthetic sequence, in which the benzyloxymethyl hydroxyl protecting group has been replaced by methoxymethyl, to avoid the apparent formation of a benzyl ester derivative as a side product. The overall yield of the new synthetic sequence is comparable to the previous one. Two advantages of the new procedure are: (a) no benzyl ester was formed and (b) a stereoisomeric mixture of syn- and anti-alcohols at the beginning of the synthetic sequence could be separated and the rest of the synthesis could be carried out with the main syn-stereoisomer instead of the corresponding stereoisomeric mixture as it was the case in the previous process. Additionally, several functional 2,8-ethanonoradamantane derivatives have been prepared.